Nelson v. Secretary of Health and Human Services

Fed. Cl.11/3/2025
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[[COURTLISTENER_SUBOPINION {"id":"11196215","type":"010combined","part":"opinion","author":null,"source_field":"html_with_citations"}]]
In the United States Court of Federal Claims
                                  OFFICE OF SPECIAL MASTERS
                                           No. 18-1144V
                                       Filed: October 2, 2025

    ************************* *
                                *
    KATHRYN NELSON,             *
                                *
                                *
                    Petitioner, *
                                *
    v.                          *
                                *
                                *
    SECRETARY OF HEALTH AND     *
    HUMAN SERVICES,             *
                                *
                                *
                    Respondent. *
                                *
    ************************* *

Kathleen Loucks, Lommen Abdo Law Firm, Minneapolis, MN, for Petitioner;
James Lopez, U.S. Department of Justice, Washington, DC, for Respondent.

                              DECISION DENYING ENTITLEMENT1

Shah, Special Master:

         On August 6, 2018, Kathryn Nelson (“Petitioner” or “Ms. Nelson”) filed a petition for
compensation under the National Vaccine Injury Compensation Program, 42 U.S.C. § 300aa-10,
et seq.2 (the “Vaccine Act” or “Program”), alleging that she suffered from Guillain-BarrĂ©
syndrome (“GBS”) as a result of the influenza (“flu”) vaccine she received on October 21, 2015.
Pet. at 1.



1
  Because this Decision contains a reasoned explanation for the action in this case, it must be made publicly
accessible and will be posted on the United States Court of Federal Claims' website, and/or
at https://www.govinfo.gov/app/collection/uscourts/national/cofc, in accordance with the E-Government
Act of 2002.
44 U.S.C. § 3501
note (2018) (Federal Management and Promotion of Electronic Government
Services). This means the Decision will be available to anyone with access to the internet. In
accordance with Vaccine Rule 18(b), Petitioner has 14 days to identify and move to redact medical or other
information, the disclosure of which would constitute an unwarranted invasion of privacy. If, upon review,
I agree that the identified material fits within this definition, I will redact such material from public access.
2
 National Childhood Vaccine Injury Act of 1986,
Pub. L. No. 99-660, 100
Stat. 3755. Hereinafter, for ease
of citation, all “§” references to the Vaccine Act will be to the pertinent subparagraph of 42 U.S.C. § 300aa
(2012).
                                                       1
        For the reasons discussed in this decision, I conclude that Petitioner has failed to establish
entitlement to compensation. First, Petitioner has not proven a Table injury, because the evidence
shows the onset of her GBS was the same day as the subject flu vaccination. Second, Petitioner
has not met her burden of preponderantly demonstrating the flu vaccine was a cause-in-fact of her
GBS. Her GBS was more likely caused by a Campylobacter jejuni (“C. jejuni”) infection, and its
onset was too soon to causally implicate the vaccine. Accordingly, the petition is dismissed.

I.     PROCEDURAL HISTORY

       Petitioner filed medical records and an affidavit on August 6 and 10, 2018, and January 17,
2019. ECF Nos. 1.2, 8-11, 29, 31. On April 26, 2019, Respondent filed a status report identifying
additional outstanding medical records. ECF No. 36. Petitioner filed additional records on June
7 and July 25, 2019. ECF No. 38.

        On October 28, 2019, Respondent filed his Rule 4(c) report, arguing that this case is not
appropriate for compensation because preponderant evidence supports C. jejuni infection as the
alternative cause of Petitioner’s GBS. ECF No. 50 (“Report”) at 19.

       Petitioner filed additional medical records on November 20, 2019. ECF No. 51.
Respondent filed a status report on January 10, 2020, stating that he was unwilling to engage in
informal settlement negotiations. ECF No. 56.

        On April 14, 2020, Petitioner filed an expert report from Praful Kelkar, M.D., along with
his curriculum vitae and supporting medical literature. Exs. 40-49. Respondent filed an expert
report, curriculum vitae, and literature from Kathleen Collins, M.D., Ph.D., on November 20,
2020. Exs. A, Tabs 1-17, Ex. B. Dr. Kelkar submitted a supplemental expert report and literature
on March 9, 2021, and a letter further summarizing his opinion on November 3, 2021. Exs. 50-
57. Dr. Collins submitted a supplemental expert report on July 6, 2021. Ex. C. On February 15,
2022, Petitioner filed a second supplemental report and additional literature from Dr. Kelkar. Exs.
58-70.

        On October 5, 2021, former Special Master Katherine E. Oler held a status conference with
the parties at which she stated her preliminary opinion on the case. ECF No. 76. Special Master
Oler stated that two major issues with Petitioner’s claim were (1) she tested positive for C. jejuni;
and (2) Petitioner’s back pain appeared to have started within just 48 hours of receiving the
allegedly causal flu vaccine. Id. She recommended that Petitioner consider dismissing her case.
Id.

        On November 4, 2021, Petitioner filed a status report requesting a fact ruling limited to
“the sole issue as to whether the C. jejuni infection and the vaccine both contributed to cause
GBS.” ECF No. 79. Special Master Oler held another status conference on November 10, 2021,
at which she explained that a fact ruling would not resolve the question of the cause(s) of
Petitioner’s GBS. ECF No. 80. Petitioner’s counsel stated that Petitioner wished to file an
additional expert report, which she did on February 15, 2022. Id.; Ex. 58. Respondent filed an
additional expert report on June 17, 2022. Ex. D, Tabs 1-3.


                                                  2
        On August 22, 2022, Petitioner filed a motion for a ruling on the record (“Motion”). ECF
No. 87. Respondent filed a response (“Response”) on October 21, 2022, and Petitioner filed a
reply (“Reply”) on December 5, 2022. ECF Nos. 88, 89. Respondent filed a sur-reply (“Resp’t’s
Sur-Reply”) on January 20, 2023, and Petitioner filed her own sur-reply (“Pet’r’s Sur-Reply”) on
February 16, 2023. ECF Nos. 91, 92. On March 2, 2023, the parties filed a joint status report
indicating that the record was complete. ECF No. 93.

        After further review of the record, on March 29, 2024, Special Master Oler issued an order
directing the parties to file supplemental expert reports addressing several questions relating to the
issues of onset and alternative causation. ECF No. 95. She also directed Petitioner to file a
supplemental declaration. Id.

         On April 29, 2024, Petitioner filed her declaration. Ex. 71. On June 27, 2024, Respondent
filed a report and literature from Dr. Collins addressing Special Master Oler’s questions; the next
day, Petitioner filed a report from Dr. Kelkar responding to those questions. Ex. E, Tabs 1-7; Ex.
72.

       On August 13, 2024, this case was reassigned to my docket. ECF No. 102. The case is
now ripe for adjudication.

II.      FACT EVIDENCE

      A. Pre-Vaccination Medical History

        Petitioner was 80 years old at the time of the subject flu vaccination. She had an extensive
pre-vaccination medical history that was significant for gastroesophageal reflux disease
(“GERD”), hypertension, gout, hyperlipidemia, multinodular goiter, macular degeneration,
osteoarthritis of the knees, hips, and left foot, juvenile rheumatoid arthritis, Sjogren’s syndrome
with parotitis, cervical spinal stenosis, osteoporosis, diverticulosis, carpal tunnel syndrome
requiring surgery, Lyme disease, and left retinal artery occlusion. Ex. 16 at 10-15; Ex. 21 at 78-
80, 85-86, 89; Ex. 27 at 2; Ex. 29 at 63; see also Ex. 71 at 1 (Petitioner’s Affidavit).

        In September 2015, Petitioner sustained a left toe fracture after falling down a bluff. See
Ex. 19 at 9; Ex. 36 at 116. She had surgery to reduce the fracture on September 23, 2015. Ex. 37
at 1-2. At discharge, she was given prescriptions for Vicodin, Vistaril,3 ibuprofen, and Senokot.
Ex. 19 at 44.

       On October 8, 2015, Petitioner had a follow-up visit with her foot surgeon. Ex. 37 at 3.
She reported no pain but had some swelling and tenderness with motion of the injured foot. Id. A


3
  Vistraril: trademark for preparations of hydroxyzine. DORLAND’S MEDICAL DICTIONARY ONLINE
(“DORLAND’S”), https://www.dorlandsonline.com/dorland/definition?id=53275 (last accessed on
September 18, 2025); Hydroxyzine: a piperazine derivative with central nervous system depressant,
antispasmodic,       antihistaminic,     and      antifibrillatory    actions.          DORLAND’S,
https://www.dorlandsonline.com/dorland/definition?id=23563 (last accessed on September 18, 2025).

                                                  3
peripheral neurovascular exam revealed “intact sensation to light touch and intact gross motor
function.” Id. Her sutures were removed, and she was referred to physical therapy (“PT”). Id.

       On October 21, 2015, Petitioner saw podiatrist Christina Knutson, D.P.M., of the Stillwater
Medical Group, for bilateral foot numbness. Ex. 36 at 137-39. At the time of the visit, she was
wearing a surgical shoe following her surgery. Id. at 137. Dr. Knutson recorded a history of
midfoot arthritis for which Petitioner had received past corticosteroid injections. Id. Petitioner
reported that she had experienced numbness in all toes on both feet, particularly the central toes.
Id. She relayed that an earlier EMG had showed latency in the peroneal nerve,4 but she did not
have numbness in that region. Id. She described the numbness in her feet as “bothersome” but
not particularly painful. Id. It had not worsened. Id. She was concerned she might have a
neuroma.5 Id.

        On exam, Petitioner had normal strength but had pain in the second and third
intermetatarsal spaces of both feet, with the left foot more painful. Ex. 36 at 137. She had bilateral
hammertoe deformities of the second toe. Id. She had no pain with palpation but had restricted
range of motion of the midfoot. Id. She had a negative “Mulder click.”6 Id. Dr. Knutson’s
differential included neuroma and peripheral neuropathy. Id. at 138. Possible causes of
Petitioner’s numbness included hypothyroidism, mechanical or hereditary neuropathy, vitamin
deficiency, or unknown etiology. Id. Dr. Knutson administered injections of Marcaine and
dexamethasone into the feet. Id. The goal was to rule out neuroma as the cause of the numbness.
Id. She advised Petitioner to monitor her symptoms for 10 days and, if her numbness improved,
consider receiving an injection into the second intermetatarsal space. Id.

       Petitioner received the subject flu vaccination during her visit with Dr. Knutson on October
21, 2015. Ex. 1 at 4.

    B. Post-Vaccination Medical History

       According to Petitioner’s supplemental declaration, she drove from Minnesota to Florida
on about October 27-28, 2015. Ex. 71 at 1.




4
  Peroneal nerve: The peroneal nerve is on the outside of the fibula just below the knee. Pressure to the
peroneal nerve, as you might experience if you sit with your legs crossed for too long, can trigger temporary
foot      drop.           MAYO        CLINIC,         https://www.mayoclinic.org/diseases-conditions/foot-
drop/multimedia/peroneal-nerve/img-20008172 (last accessed September 18, 2025).
5
 Neuroma: a tumor growing from a nerve or made up largely of nerve cells and nerve fibers. DORLAND’S,
https://www.dorlandsonline.com/dorland/definition?id=33770 (last accessed September 17, 2025).
6
  Mulder sign: when the foot is compressed from the sides and the involved distal metatarsal space is
digitally compressed, if a Morton neuroma is present the involved nerve will snap below the metatarsal
heads, sometimes making an audible click. Called also Mulder click.                      DORLAND’S,
https://www.dorlandsonline.com/dorland/definition?id=106378 (last accessed September 17, 2025).

                                                     4
        Eight days after the vaccination, on October 29, 2015, at 4:15 a.m., Petitioner was seen in
the emergency room (“ER”) of Venice Regional Medical Center (“VRMC”) in Florida, for nausea
and sharp, non-radiating pain in her left mid-back since 3 a.m. the previous night, October 28. Ex.
29 at 6. She had taken an oxycodone the previous evening for the pain. Id. She denied vomiting,
abdominal pain, or diarrhea. Id. at 11. She reported that she “[j]ust drove here from Minnesota.”
Id.

        Petitioner’s examination was unremarkable, and the ER physician suspected her symptoms
were musculoskeletal in origin. Ex. 29 at 13. A CT scan of the lumbar spine showed a possible
large hemangioma in the T12 vertebral body with a “corduroy appearance.”7 Id. at 22. Petitioner
was discharged home with a diagnosis of back pain and nausea/vomiting. Id. at 15. She was given
prescriptions for Zofran for nausea, Percocet for pain, and Colace, a laxative. Id.

       At 2:45 p.m. on October 30, 2015, Petitioner saw her Florida primary care physician
(“PCP”), Christopher Jefferson, M.D., in the office. Ex. 21 at 87. Dr. Jefferson’s notes reflect the
following:

          Patient is here today after follow-up in the emergency room. When she was there
          she was nauseous she was vomiting she had a significant pain in her back and
          radiated to her back I thought maybe it was pancreatitis her (sic) UTI at that time
          so we sent her over to the emergency room to get looked at the urine had a couple
          of cells in it but was minimally affected but it did not look like a urine infection.
          And she had a pancreatic enzymes which were negative she also had a CAT scan
          that was done as well that did not show anything significant as well. She’s here
          today to have a follow-up exam done and to see if there is anything else that could
          be done to improve her symptoms. Pain in the back was first. Had 1 day of dry
          heaves for 24 hours then gone. It was about a month ago. 3 am a couple of days
          ago, took a [pain] med as well, Pepcid AC in the car getting down here. Again in
          the morning Prilosec and Amoxicillin as well had taken for the stomach as well.
          Took something else for the back pain and took her Prednisone8 as well for 6
          days. Everything seemed to get worse when she did the prednisone about 4 days
          later which makes me think she may have an ulcer there. Organ [sic] put her on
          Dexilant twice a day Carafate 4 times a day and give her ondansetron pills to take
          and as a Phenergan backup as well at this time and I will give her a call on Monday
          and see how she [is] doing at that time. We’ll also be able to get the urine culture
          that was done in the emergency room and should have it’s [sic] final report back by
          then as well.

Ex. 21 at 87 (emphasis added). Dr. Jefferson noted that Petitioner had received “[a] recent
immunization for flu[;] Doctor up north.” Id. at 88. A Review of Systems (“ROS”) indicated that
she had nausea and abdominal pain but no diarrhea or chronic constipation. Id. at 90.

7
 A CT scan of the abdomen and pelvis showed chronic diverticular disease in the colon but was otherwise
normal. Ex. 29 at 23.
8
    It is unclear when or for what purpose Petitioner was prescribed prednisone.

                                                      5
       On exam, Petitioner had a temperature of 99.7°F. Ex. 21 at 90. She did not have motor
dysfunction or paralysis, and her balance, gait, and stance were normal. Id. at 92. Dr. Jefferson’s
impressions were gastric ulcer, abdominal pain, nausea with vomiting, and dehydration. Id.

       On October 31, 2015, Petitioner called 911 and EMS arrived at her home. Ex. 29 at 37.
She complained of weakness for four days since arriving in Florida. Id. She reported that she had
seen her doctor for back pain and that the pain medication he prescribed made her sick to her
stomach and caused vomiting. Id. Her echocardiogram showed atrial fibrillation, and EMS
transported her to the VRMC ER. Id.

        At VRMC, Petitioner was seen by Dr. Jefferson again. Ex. 29 at 50. He recounted that
Petitioner had been seen in the ER the morning of October 29, 2015, and provided a more detailed
history of her course:

       She was seen [in the ER] about 3 o’clock in the morning as she woke up with
       significant abdominal pain that was radiating to the back was actually more back
       pain than anything else. The abdominal pain got better. The radiating pain got
       worse and it felt like it was in the pit of her stomach radiating to the back. She went
       to the emergency room for evaluation and had a CAT scan that was done that was
       negative and had blood tests that were done showing creatinine was at 1.6.
       Potassium was normal. Sodium was normal. Magnesium was normal. Urinalysis
       was normal as well and she was sent home after IV fluids and hydration at that
       time. [S]he came into our office yesterday and I saw her at the end of the day. She
       is still complaining of the same pain radiating to her back and again thought it was
       either pancreatitis or UTI, which were both negative with negative enzymes and
       negative urine cultures, she had not made any improvement[.] [L]ooking back at
       the history before this happened is (sic) started about a week before, she had a
       day of dry heaves for 24 hours and then it was gone and then it happened again
       a couple of days later and it was more of the acute onset of symptoms at that
       point. O[f] interest, she had been having some back pain prior to that and had
       taken a course of prednisone for 6 days she says and then had stopped it a couple
       of days after that is when she started to get more of the abdominal symptoms
       radiating to the back, thought it could possibly be an ulcer, so yesterday we put
       her on Dexilant twice a day, [C]arafate liquid 4 times a day, ondansetron pills,
       Phenergan as a backup and she was supposed to follow up with this on Monday.
       [S]he went home and as the night went on, she got more miserable got to the point
       where her legs got weak and she tried to get up with a walker and as the night went
       on, she had a couple of falls and decided it was time to come into emergency room
       to get evaluated. [W]hen she came in this time, her sodium was down to 129. Her
       potassium was normal, creatinine was up to 2.2. Her white count was over 14,000
       and it looks like she was some hemoconcentration as well with dehydration and her
       legs were so weak that she could not bear weight on them. She is being given IV
       fluids, she is feeling somewhat better. The nausea that she had before is completely
       gone at this time, which is good. [S]he complains more that her back hurts than
       anything else at this point, but the nausea part is gone so hopefully with the fluids
                                                 6
        and hydration that she got hopefully that is going to make a difference and get her
        back up, but she is needing management of the electrolyte imbalance and a workup
        of the leukocytosis at this time and we will do that workup during her
        hospitalization, which will take 2 midnights and we will see how she does with the
        electrolyte replacement.

Id. (emphasis added).

        A ROS was positive for weakness and fatigue but negative for nausea, vomiting, or
abdominal pain at that time. Ex. 29 at 51. A physical exam was unremarkable. Id. Dr. Jefferson’s
assessment was that Petitioner had abdominal pain of uncertain etiology, severe dehydration, and
nausea and vomiting that was improved with Zofran. Id. His plan was to admit her to the hospital
to do blood cultures to look for infection and other tests. Id. at 52.

        That same day, Petitioner saw gastroenterologist Peter Dumas, M.D., for “recalcitrant
nausea and vomiting.” Ex. 29 at 53. On exam, Dr. Dumas was unable to assess Petitioner’s gait
because she was too weak to walk. Id. at 54. His impression was acute, severe epigastric pain,
acute nausea and vomiting, dehydration, and hyponatremia. Id. He suspected gastric ulcer or
gastric   carcinoma,     recommended       continuing    IV    fluids,  and    ordered     an
esophagogastroduodenoscopy (“EGD”). Id. The EGD was not performed because of Petitioner’s
weakness and electrolyte imbalances. Id. at 80.

        The next day, November 1, 2015, Petitioner saw Tonya Stephenson, M.D., for a neurology
consultation. Ex. 29 at 56. The history noted that Petitioner developed abdominal pain that
radiated to her back beginning early Thursday, October 29. Id. She was “on prednisone for the
back pain.” Id. After being discharged from the ER, she developed 24 hours of dry heaves. Id.
Then, either late Friday or early Saturday, she experienced a fall due to weakness. Id. Petitioner
also reported that, “prior to her illness, she had a little bit of tingling and numbness in the left foot,
predominantly the top of her foot.” Id. At the time of the examination, she was complaining of
tingling and numbness in the feet and hands. Id.

        Dr. Stephenson observed that Petitioner had diffuse weakness with an abrupt onset, absent
reflexes, and paresthesias. Ex. 29 at 57. Her assessment was possible GBS and possible myopathy.
Id. She ordered an MRI of Petitioner’s cervical spine and a head CT and left open the possibility
of a lumbar puncture. Id.

       That same day, Petitioner saw William Woolverton, M.D., for a cardiology consultation.
Ex. 29 at 59. Dr. Woolverton’s impression was progressive weakness suggesting a possible
primary neuromuscular disorder such as GBS, abnormal cardiac enzymes likely of a skeletal
muscle source, tachycardia secondary to dehydration with gastrointestinal losses, and
hyponatremia likely due to dehydration. Id. at 60. Dr. Woolverton ordered an echocardiogram
and continuing IV fluids. Id.

       Later that day, Petitioner saw Ahmed Farooq, M.D., for an infectious disease consultation.
Ex. 29 at 62. Petitioner reported to Dr. Farooq that, on her drive to Florida, she ate spaghetti and
spinach salad at a local restaurant in Illinois. Id. That night, she began to “feel worse,” with
                                                    7
abdominal pain and nausea, but no diarrhea. Id. “Since they were traveling and driving, they
decided to continue [to Florida].” Id. The nausea got worse after arriving in Florida, prompting
her initial ER visit early Thursday morning. Id. After being discharged from the ER, she became
progressively weaker “to the point that she was unable to walk.” Id. She went back to the hospital
on Saturday. Id. at 63.

        Petitioner told Dr. Farooq that that about a week earlier, “she stopped taking her
methotrexate” for juvenile rheumatoid arthritis. Ex. 29 at 62. Also, she “was recently given some
steroids” for back pain. Id. On exam, she exhibited significant weakness and no reflexes. Id. at
64. Dr. Farooq suspected GBS. Id. He explained that she had “profound muscle weakness” with
abdominal pain, nausea, and vomiting. Id. at 65. He commented that “[t]he only gastrointestinal
infection that can actually present like that is Campylobacter jejuni infection that will present as
[GBS].” Id. Food poisoning such as botulism was another possibility, but based on Petitioner’s
clinical presentation, Dr. Farooq did not believe that was the correct diagnosis. Id. Dr. Farooq
noted that Petitioner was likely experiencing an “autoimmune phenomenon” for which antibiotics
would not be helpful. Id. Nonetheless, he said he would order Campylobacter stool studies. Id.

       The results of a lumbar puncture showed elevated protein in the cerebrospinal fluid
(“CSF”). Ex. 29 at 68. Lyme disease testing was negative. Id. Petitioner began an eight-day
course of IVIG. Id.

       On November 2, 2015, Petitioner was transferred out of intensive care. Ex. 29 at 82. Dr.
Dumas noted that Petitioner’s GBS could have been caused by the flu vaccine, but more testing
was needed to be certain. Id. at 103-04.

        On November 3, 2015, Petitioner was seen by an infectious disease specialist who
commented that she reported receiving the “senior” dose of the flu vaccine in Minnesota in
October.9 Ex. 29 at 103. The physician noted that GBS “has always been a questionable side
effect from flu vaccine,” but, if no other cause was found, the case should be reported to VAERS.
Id.

      On November 5, 2015, Petitioner went into respiratory arrest and was intubated for one
week. Ex. 29 at 68, 83.

        On November 6, 2015, the infectious disease physician attempted to report Petitioner’s
case to VAERS but was told the clinic administering the vaccine would have to do so.10 Ex. 29 at
114. On November 7, 2015, the physician commented that serology for C. jejuni was positive. Id.
at 115, 279. The physician remarked that Petitioner’s GBS could possibly be related to C. jejuni
if the infection was recent. Id. On November 9, 2015, the physician noted that the cause of

9
 These notes and the notes from November 7 and 9, 2015 were handwritten, apparently by the same
physician, whose name was illegible.
10
  Although the records indicate the infectious disease specialist contacted the Minnesota clinic at which
Petitioner was vaccinated to request that it file a VAERS report, it is unclear whether the clinic did so. Ex.
29 at 114. No such report has been produced in this case.

                                                      8
Petitioner’s GBS was “not clear” and could have been either the recent flu vaccination or C. jejuni
infection. Id. at 120.

        On November 16, 2015, a neurologist, Dr. Coleman, noted that Petitioner had GBS “likely
triggered by influenza vaccine.” Ex. 29 at 135. That same day, Petitioner was discharged from
the hospital to HealthSouth Sarasota Rehabilitation Hospital, an inpatient rehabilitation center. Id.
at 68-69.

       On November 19, 2015, Petitioner was discharged back to VRMC. Ex. 30 at 110-12. Her
EKG showed atrial fibrillation with a rapid ventricular rate. Id. She was discharged from the
hospital on December 4, 2015, with a diagnosis of acute perforated diverticulitis. Ex. 39 at 22.
She underwent surgery for the diverticulitis that month, requiring a colostomy. See Ex. 5. She
returned to the rehabilitation facility, where she received inpatient treatment until her discharge on
December 30, 2015. Ex. 30 at 613-14. Petitioner went from there to a skilled nursing facility,
where she remained until March 9, 2016. Ex. 26 at 1-18.

        In 2016, after returning to Minnesota, Petitioner continued to follow up for her
diverticulitis. Ex. 6 at 2. On December 6, 2016, she was seen in Florida by a cancer specialist for
severe anemia. Ex. 11 at 27. She received a blood transfusion, which returned her hemoglobin
levels to normal. Id. at 67.

        On September 12, 2018, nearly three years after the vaccination, Petitioner saw neurologist
Eric Ahlskog, M.D., Ph.D., at the Mayo Clinic, for an evaluation of sequelae of her GBS. Ex. 32
at 212. Dr. Ahlskog noted that she developed GBS “after a flu shot.” Id. He also noted that her
recovery was slow, requiring six months of rehabilitation, and that it was complicated by “heart
failure,” diverticulosis with colon rupture, and an upper GI ulcer. Id. Before her illness, she was
active and “very athletic,” but afterward she required a forearm cane for balance. Id. She used a
motorized scooter. Id. She suffered paresthesias and dysesthesias distally in all of her limbs. Id.
She had more recently developed “extreme fatigue” and dyspnea on exertion. Id.

        On exam, Petitioner had reduced touch sensation in her lower legs and forearms. Ex. 32
at 213. Her vibration sense was absent in her big toes and ankles. Id. She had marked tenderness
distally in her arms. Id. She had impaired strength in both hands, but “normal or close to normal”
strength in her wrists and proximal arms. Id. She had marked weakness of the right iliopsoas and
hamstring. Id. Her toe extensors were also weak. Id.

       Dr. Ahlskog’s assessment was marked but incomplete improvement of GBS. Ex. 32 at
213. He ordered an EMG, which was done on September 18, 2018. Id. at 214. The EMG revealed
“minimally abnormal” results, with no evidence of neuropathic disease activity. Id. This surprised
Dr. Ahlskog, given Petitioner’s clinical presentation, so he consulted with another neurologist. Id.
She opined that the likely explanation was “the demyelinating attack was predominantly proximal
at nerve root entry zones[.]” Id. Both neurologists agreed that further evaluation of the
contemporaneous hospital records would be helpful to confirm the GBS diagnosis. Id. The records
produced in this case, however, do not indicate this evaluation was completed.



                                                  9
III.      EXPERT EVIDENCE

       A. Praful Kelkar, M.D.: First Expert Report

       Dr. Kelkar received his medical degree from the University of Bombay in 1983. Ex. 41
(“Kelkar CV”) at 1. He completed his residency in internal medicine in 1987 and additional
residencies in internal medicine and neurology in the United States between 1988 and 1992. Id.
He is board certified in neurology, neuromuscular and electrodiagnostic medicine with a
subspecialty in neuromuscular medicine, and clinical neurophysiology. Id. Since 2007, he has
been an adjunct associate professor in the department of neurology at the University of Minnesota.
Id. He previously taught as an associate professor at the University of Iowa. Id.; Ex. 40 (“First
Kelkar Rep.”) at 1. He has authored or co-authored 26 peer-reviewed journal articles and three
book chapters in neurology, and he has received several research grants. Kelkar CV at 2-3, 7.

       In his first expert report, Dr. Kelkar noted that Petitioner had a complex history with
multiple chronic conditions. First Kelkar Rep. at 2. He opined that Petitioner’s GBS diagnosis
was correct, based on her clinical symptoms of pain and weakness, the elevated protein level in
her CSF, and her improvement following treatment with IVIG. Id. at 3.

        Turning to causation, Dr. Kelkar stated that C. jejuni infections are “common” and that
“GBS can be triggered by a variety of infections and the most common infection is campylobacter
jejuni.” First Kelkar Rep. at 3. Up to 30% of GBS patients are positive for C. jejuni, and one in
1,000 cases of C. jejuni are estimated to result in GBS. Id. (citing Israeli et al., Guillain-Barré
Syndrome – A Classical Autoimmune Disease Triggered by Infection or Vaccination, 42 CLINICAL
REVS. ALLERGY & IMMUNOLOGY 121-30 (2012) (Ex. 45) (“Israeli”)).

        Dr. Kelkar acknowledged that Petitioner tested positive for C. jejuni antibody. First Kelkar
Rep. at 3. He noted that the test was run by Quest Diagnostics. Id. He reported that he contacted
the medical director for Quest and was advised that their test did not distinguish between IgM,
IgA, and IgG antibodies for C. jejuni, making it impossible to determine whether Petitioner had
an active, recent, or remote C. jejuni infection. Id.

        Dr. Kelkar also stated that flu vaccination is causally linked to GBS. First Kelkar Rep. at
3. Citing the Israeli paper, he pointed out that the typical onset of GBS is 3-6 weeks following flu
vaccination, but he also said that here, the onset was “one week after the vaccination, which is
typical for vaccine related GBS.” Id. (citing Israeli).

        Petitioner therefore had two risk factors for GBS: flu vaccination and positive C. jejuni
serology. First Kelkar Rep. at 3. Dr. Kelkar noted that “[h]ow to ascertain relative risk of
developing GBS given multiple risk factors is the question,” given the scant literature “about dual
trigger factors inducing GBS.” Id. He cited literature reporting GBS after administration of both
H1N1 and seasonal flu vaccinations. Id. (citing Greene et al., Risk of Confirmed Guillain-Barré
Syndrome Following Receipt of Monovalent Inactivated Influenza A (H1N1) and Seasonal
Influenza Vaccines in the Vaccine Safety Datalink Project, 2009-2010, 175(11) AM. J.
EPIDEMIOLOGY 1100-09 (2012) (Ex. 46) (“Greene 2012”)). He also referenced reports of GBS
after dual infection with Zika and dengue virus or with C. jejuni and Yersinia pseudotuberculosis.
                                                10
Id. (citing Parra et al., Guillain-Barré Syndrome Associated with Zika Virus Infection in Colombia,
NEW ENGLAND J. MED. 375:16 (2016) (Ex. 47) (“Parra”); Amereller et al., A horse and a zebra:
an atypical clinical picture including Guillain-Barré syndrome, recurrent fever and mesenteric
lymphadenopathy caused by two concomitant infections, INFECTION (2020) (Ex. 48)
(“Amereller”)).

       According to Dr. Kelkar, C. jejuni infection is associated with the induction of anti-GM1
antibodies, which are believed to be involved in causing GBS. First Kelkar Rep. at 3. The flu
vaccine also induces anti-GM1 antibodies. Id. (citing Nachamkin et al., Anti-Ganglioside
Antibody Induction by Swine (A/NJ/1976/H1N1) and Other Influenza Vaccines: Insights into
Vaccine-Associated Guillain-Barré Syndrome, 198 J. INFECTIOUS DISEASES 226-33 (2008) (Ex.
44) (“Nachamkim”)). “Mechanisms such as this may explain [the] synergistic effect of two
concomitant risk factors inducing GBS.” Id.

        Dr. Kelkar opined that the subject flu vaccine “probably” caused Petitioner’s GBS. First
Kelkar Rep. at 4. He considered the vaccine to be a more significant factor than a C. jejuni
infection because the infection “was not entirely proven” with the serology results. Id.
Additionally, he opined that Petitioner did not develop the type of GBS most often associated with
a C. jejuni infection. Id. C. jejuni usually causes axonal GBS, which involves a much slower
recovery and a much poorer outcome than the demyelinating form of GBS, acute inflammatory
demyelinating polyneuropathy (“AIDP”). Id. (citing D. Chowdhury & A. Arora, Axonal Guillain-
Barré syndrome: a critical review, 103 ACTA NEUROLOGICA SCANDINAVICA 267-77 (2001) (Ex.
42) (“Chowdhury & Arora”)). In Dr. Kelkar’s view, Petitioner more likely had AIDP, based on
her quick response to IVIG therapy and her “nearly normal” EMG after her GBS, which are not
consistent with axonal GBS. Id.

   B. Kathleen Collins, M.D., Ph.D.: First Expert Report

        Dr. Collins earned her medical degree and doctorate from Johns Hopkins University in
1993. Ex. B (“Collins CV”) at 1. She completed her residency in internal medicine in 1995 and
clinical and research fellowships in infectious disease from 1995-1998. Id. Since 1998, she has
held clinical and academic professorships at the University of Michigan in internal medicine and
microbiology and immunology. Id. She is the recipient of numerous research grants. Id. at 3-6.
She has authored or co-authored 40 peer-reviewed journal articles and five book chapters, with a
particular focus on immunology and HIV. Id. at 14-20.

         Dr. Collins did not dispute that Petitioner developed GBS. She took issue, however, with
the claim that seasonal flu vaccination can cause GBS. First Collins Rep. at 5-6. She cited several
epidemiologic studies reporting no increased risk of GBS following flu vaccination. Id. at 5-7.
First, she noted that the Israeli article cited by Dr. Kelkar did not “actually support [Dr. Kelkar’s]
claim that influenza vaccination has been linked to [GBS].” Id. at 5 (citing Israeli). That paper
did support a link between C. jejuni infection and GBS. Id. The Israeli paper also cited Stowe et
al., in which the authors found no increased risk of GBS after seasonal flu vaccination. Id. at 6
(citing Julia Stowe et al., Investigation of the Temporal Association of Guillain-Barré Syndrome
With Influenza Vaccine and Influenzalike Illness Using the United Kingdom General Practice
Research Database, 169 AM. J. EPIDEMIOLOGY 382-88 (2008) (Ex. A, Tab 2) (“Stowe”)).
                                                 11
        Dr. Collins also referenced an article by Grimaldi-Bensouda, which reported an association
between flu infection (or infection with flu-like symptoms) and GBS, but no association between
the flu vaccine and GBS. First Collins Rep. at 6 (citing Grimaldi-Bensouda et al., Guillain-Barré
Syndrome, Influenza-like Illnesses, and Influenza Vaccination During Seasons With and Without
Circulating A/H1N1 Viruses, 174 AM. J. EPIDEMIOLOGY 326-35 (2011) (Ex. A, Tab 3) (“Grimaldi-
Bensouda”)). Similarly, the Greene study found that the 2009 and 2010 seasonal flu vaccines did
not pose an elevated risk of GBS. Id. at 6-7 (citing Greene et al., Guillain-Barré Syndrome,
Influenza Vaccination, and Antecedent Respiratory and Gastrointestinal Infections: A Case-
Centered Analysis in the Vaccine Safety Datalink, 2009-2011, 8 PLOS One 1-10 (2013) (Ex. A,
Tab 1) (“Greene 2013”)). The Vellozzi study reported a lower risk of GBS following H1H1
influenza vaccination than in unvaccinated populations. Id. at 8 (citing Vellozzi et al., Cumulative
Risk of Guillain-Barré Syndrome Among Vaccinated and Unvaccinated Populations During the
2009 H1N1 Influenza Pandemic, 104(4) AM. J. PUB. HEALTH 696-701 (2014) (Ex. A, Tab 4)
(“Vellozzi”)). Finally, the Baxter study found no evidence of increased risk of GBS following any
type of vaccination, including flu. Id. (citing Baxter et al., Lack of Association of Guillain-Barré
Syndrome With Vaccinations, 57(2) CLINICAL INFECTIOUS DISEASES 197-204 (2013) (Ex. A, Tab
7) (“Baxter”)).

        Next, Dr. Collins pointed out that C. jejuni infection is “strongly associated with [GBS].”
First Collins Rep. at 8. She noted that about 70% of GBS patients reported a “prior history of
diarrhea[.]” Id. The mean time between onset of diarrhea and GBS symptoms was nine days. Id.
(citing Rees et al.). A history of C. jejuni infection “has been reported in 26-60% of [GBS] cases.”
Id. C. jejuni infection is associated with an up to 60-fold increased risk of GBS. Id. (citing Tam
et al., Guillain-Barré Syndrome and Preceding Infection with Campylobacter, Influenza and
Epstein-Barr Virus in the General Practice Research Database, 4(344) PLOS ONE 1-6 (2007) (Ex.
A, Tab 9) (“Tam”)). The Tam authors reported up to a 38-fold increased risk of GBS in the two
months following C. jejuni infection, but a non-statistically significant lowered risk of GBS
following flu vaccination. Id. (citing Tam at 2 (Table 1)).

        Dr. Collins explained that one type of GBS associated with C. jejuni infection is acute
motor axonal neuropathy (“AMAN”). First Collins Rep. at 8. AMAN is believed to be caused by
molecular mimicry between components of nerve axons and the antibody response to the infection.
Id. The Nodes of Ranvier, which are gaps in the myelin sheath covering the nerve, “are a major
target of the antibody response.” Id. at 9 (citing Hahn et al., Guillain-BarrĂ© syndrome, 352 THE
LANCET 635-41 (1998) (Ex. A, Tab 11) (“Hahn”); van Doorn, et al., Clinical features,
pathogenesis, and treatment of Guillain-Barré syndrome, 7 LANCET NEUROLOGY 939-50 (2008)
(Ex. A, Tab 12) (“van Doorn”)). Rabbits sensitized to C. jejuni developed anti-GM1 antibodies,
limb weakness, and nerve changes mimicking AMAN. Id. (citing Yuki et al., Guillain-Barré
Syndrome (2004)). The animals had more pronounced degeneration at the nerve roots, “which
have less blood-nerve barrier and greater access of neurons to antibodies.” Id. (citing Yuki et al.,
Carbohydrate mimicry between human ganglioside GM and Campylobacter jejuni
lipoligosaccharide causes Guillain-Barré syndrome, Proceedings of the National Academy of
Sciences, 2004. 101(31): p. 11404-11409 (2004) (Ex. A, Tab 13) (“Yuki 2004”)).



                                                12
        Dr. Collins disagreed with Dr. Kelkar’s theory that the flu vaccine and a C. jejuni infection
could have caused Petitioner’s GBS together. First Collins Rep. at 10. She opined that Dr. Kelkar
presented no evidence to support the interaction between the vaccine and infection and that his
reliance on the Greene article was “misleading” because the authors did not find that vaccination
increased the risk of developing GBS. Id. (citing Greene 2012). She likewise criticized Dr.
Kelkar’s reliance on Nachamkin because that paper’s authors did “not believe modern influenza
vaccines are a risk factor for [GBS].” Id. (citing Nachamkin). Furthermore, in Sivadon-Tardy,
GBS patients with preceding influenza A infection were found not to have antiganglioside
antibodies. Id. at 10-11.11 Dr. Collins commented that “[i]f the natural infection does not produce
these antibodies, it is very unlikely that the vaccine does.” Id. at 11.

        Dr. Collins critiqued Dr. Kelkar’s claim that Petitioner’s GBS was less likely caused by C.
jejuni because she did not have a presentation consistent with that cause. First Collins Rep. at 11.
She noted that Sivadon-Tardy found C. jejuni-associated GBS was more likely to require
mechanical ventilation, as happened with Petitioner, than GBS caused by flu infection or
vaccination. Id. She also disagreed with Dr. Kelkar’s view that C. jejuni was an unlikely cause
of Petitioner’s GBS because that would have produced a slower recovery and a worse outcome.
Id. The article Dr. Kelkar cited, Chowdhury & Arora, referenced a different paper, Ho et al., which
found a “comparable” rate of recovery in AMAN and AIDP patients.12 Id. Furthermore, a study
by Hiraga measured rates of recovery of AMAN and AIDP patients and concluded that “AMAN
electrodiagnosis is not always a marker of poor recovery.” Id. (citing Hiraga et al., Recovery
patterns and long term prognosis for axonal Guillain-Barre syndrome, 75 J. NEUROLOGY
NEUROSURGERY & PSYCHIATRY 719-22 (2005) (Ex. A, Tab 16) (“Hiraga”)). Moreover, Petitioner
met the criteria for “slow recovery” as defined in the Hiraga study, undermining Dr. Kelkar’s claim
that she had a milder disease than would be expected in C. jejuni-caused GBS. Id.
       Dr. Collins further explained that C. jejuni infection can also be associated with AIDP.
First Collins Rep. at 9, 11. The Chowdhury & Arora paper acknowledged that both axonal and
AIDP cases have been described in association with C. jejuni infection. Id. at 11 (citing
Chowdhury & Arora).

        Lastly, Dr. Collins opined that “the timing of the vaccination relative to the onset of
symptoms does not support the vaccine causing [GBS].” First Collins Rep. at 12. Petitioner’s
reported use of prednisone for six days, plus approximately two days before she first went to the
ER, indicated that her symptoms started at least eight days prior to October 31, which would have
been only two days after vaccination. Id. Onset of GBS within 48 hours is too short a period to
infer vaccine causation. Id.

11
     Respondent did not file the Sivadon-Tardy paper.
12
   Dr. Collins explained that Ho investigators also conducted laboratory experiments suggesting quick
recovery in AMAN could be due to anti-GM1 antibodies, such as those thought to be produced in response
to C. jejuni infection, disrupting nerve conduction at the Nodes of Ranvier without causing permanent
damage. Respondent did not file the Ho paper into the record.

                                                        13
   C. Dr. Kelkar’s Second Report

         Dr. Kelkar first addressed the onset of Petitioner’s GBS symptoms following vaccination.
Ex. 50 (“Second Kelkar Rep.”) at 1. He pointed out that, although GBS typically begins within
the first three to six weeks after vaccination, “[o]nset of GBS within the first week after an inciting
event (such as infection or vaccination) is perfectly within the expected range.” Id. (referencing
Israeli).

        Second, Dr. Kelkar argued Petitioner’s symptoms did not suggest she had a C. jejuni
infection. Second Kelkar Rep. at 2. She did not develop diarrhea, a fever, an elevated white blood
count, or gastroenteritis. Id. The Nandkishor case report of C. jejuni involved a patient with
abdominal pain without diarrhea, but, unlike Petitioner, that patient had a fever and required
antibiotic treatment. Id. (citing Nandkishor et al., Enterocolitis without diarrhoea in an adult
patient: a clinical dilemma, BMJ CASE REPS. (2014) (Ex. 56) (“Nandkishor”)). Furthermore,
Petitioner “did not have positive blood or stool culture for Campylobacter.” Id.

        Third, Dr. Kelkar commented that pain is “often associated with GBS and can be a
presenting symptom of the GBS.” Second Kelkar Rep. at 3 (citing Yao et al., Pain during the
acute phase of Guillain-BarrĂ© syndrome, 97 MEDICINE 34-38 (2018) (Ex. 54) (“Yao”); L. Ruts et
al., Pain in Guillain-Barré syndrome: A long-term follow-up study, 75 NEUROLOGY 1439-47
(2010) (Ex. 52) (“Ruts”); D.E. Moulin et al., Pain in Guillain-BarrĂ© syndrome, 48 NEUROLOGY
328-31 (1997) (Ex. 51) (“Moulin”)). In particular, pain radiating to the back is “extremely
common with GBS” and is often the presenting symptom. Id.

        Fourth, Dr. Kelkar maintained that axonal GBS is more commonly associated with C.
jejuni infection and statistically results in poorer outcomes than AIDP. Second Kelkar Rep. at 4
(citing Rees et al., Campylobacter Jejuni Infection and Guillain-Barré Syndrome, NEW ENGLAND
J. MEDICINE (1995) (Ex. 55) (“Rees”)). He disagreed that Petitioner developed axonal
GBS/AMAN, instead arguing that she developed AIDP. Id. This is because she recovered quickly
with IVIG therapy, “with successful extubation within [one] week,” and had a nearly normal EMG
“one year later.” Id. at 5. Furthermore, her blood work did not confirm an acute C. jejuni infection.
Id.

         Dr. Kelkar concluded: “It is my opinion that the vaccination played an important role in
development of GBS (AIDP) and that it is more likely than not, to a reasonable degree of medical
certainty, that the influenza vaccine served as a trigger for [Petitioner’s] GBS.” Second Kelkar
Rep. at 5.

   D. Dr. Kelkar’s Supplemental Letter

       In a supplemental letter clarifying his opinions, Dr. Kelkar stated that Petitioner developed
a severe case of AIDP, which would not have occurred “but for the flu vaccine.” Ex. 57 (“Kelkar

                                                  14
Letter”) at 1. A C. jejuni infection might have also contributed to her GBS, but, in his opinion,
“the flu vaccine played a greater role in causing GBS than did the infection and was a substantial
contributing factor in causing Petitioner’s GBS.” Id.

   E. Dr. Collins’s Second Report

       Dr. Collins disputed Dr. Kelkar’s claim that Petitioner developed GBS one week after the
vaccination. Ex. C (“Second Collins Rep.”) at 1. Instead, the records “strongly support[ed] the
conclusion that symptoms actually began too soon after vaccination to have been caused by
vaccination.” Id. “[D]ays or even weeks are needed for the immune system to respond to an
antigen.” Id.

       With respect to C. jejuni-related GBS, Dr. Collins also commented that the latency period
between exposure to C. jejuni and development of GBS symptoms “must be longer than [two]
days” because the infection has an incubation period prior to the development of diarrhea. Second
Collins Rep. at 2. In humans, the median interval between the onset of diarrheal illness and
neuropathic symptoms was nine days. Id. (citing Rees).

        Dr. Collins further opined that Dr. Kelkar’s theory that the flu vaccine caused Petitioner’s
GBS did not account for the abdominal symptoms she reported, including “recalcitrant nausea and
vomiting.” Second Collins Rep. at 2-3. She stated that Dr. Kelkar had not provided any evidence
that these symptoms are associated with vaccine-induced GBS. Id. at 3. Conversely, the fact that
Petitioner did not develop diarrhea did not rule out an acute or recent C. jejuni infection in her
case. Id. at 2 (citing Rees; Nandkishor). Also, there is evidence that intestinal infections other
than C. jejuni can cause GBS. Id. at 4 (citing Tam at 2 (Table 1)). Thus, even if Petitioner did not
have C. jejuni-caused GBS, “other microbes causing an indistinguishable symptom complex of
‘intractable nausea and vomiting’ could also cause [GBS] and this would be more likely than the
vaccine [to cause] GBS.” Id.

   F. Dr. Kelkar’s Third Report

        Dr. Kelkar explained that he has treated more than 100-150 GBS patients during his 25-
year career, of which about 20-30 had C. jejuni infections. Ex. 58 (“Third Kelkar Rep.”) at 1. He
pointed out that GBS is generally understood as a post-infectious or post-inflammatory
autoimmune reaction affecting the peripheral nerves, likely produced by molecular mimicry. Id.
at 5. Studies have confirmed that “certain formulations of the influenza vaccination, most notably
the 1975 to 1976 swine flu and 2009 H1-N1 vaccines, have been clearly associated with increased
incidents [sic] of GBS.” Id. Seasonal flu vaccines have also been associated with increased risk
of GBS. Id. at 5-6 (citing Arias et al., Guillain-Barré syndrome and influenza vaccines: A meta-
analysis, 33 VACCINE 3773-3778 (2015) (Ex. 65) (“Arias”)).

        Dr. Kelkar opined that “[a]utoimmune disorders sometimes are related to two or more
triggers resulting in synergist[ic] effects,” such as two unrelated infections or infection and
                                                15
vaccination. Third Kelkar Rep. at 8 (citing Westall et al., Cause and prevention of postvaccinal
neuropathies in light of a new theory of autoimmunity, LANCET 8501: 251-52 (1986) (Ex. 67)
(“Westall”)). He added that the first trigger (the flu vaccine in Petitioner’s case) primes the
immune system, and the second (“possible” C. jejuni “or other infection”) “results in immune
activation resulting in GBS. Id. (citing Wirguin et al., Induction of anti-GM1 ganglioside
antibodies by Campylobacter jejuni lipopolysaccharides, 78 J. NEUROIMMUNOLOGY 138-42
(1997) (Ex. 68) (“Wirguin”)). He argued that this priming and triggering relationship could
explain why no particular wild infection has been conclusively linked to autoimmune diseases
such as GBS. Id. (citing Cusick et al., Molecular Mimicry as a Mechanism of Autoimmune
Disease, 42 CLINICAL REV. ALLERGY & IMMUNOLOGY 102-11 (2011) (Ex. 69) (“Cusick”)).

        Dr. Kelkar acknowledged that Petitioner complained of nausea and abdominal pain on
October 29 and 30, 2015, had a low-grade fever on October 30, and had a positive serology test
for C. jejuni on November 1. Third Kelkar Rep. at 7. He nevertheless did not feel that Petitioner
had an active C. jejuni infection during this time, based on the absence of diarrheal illness, the
opinions of Drs. Farooq and Dumas, the fact that Petitioner was never treated with antibiotics, and
the lack of specificity of the serology testing as to whether Petitioner’s exposure to C. jejuni was
recent or remote. Id. He added that “[e]ven if she had a minor or inactive c. jejuni infection, more
likely than not it was a combination of both – vaccine and infection – that led to GBS.” Id. at 8.

        Dr. Kelkar opined that, if Petitioner did not have an active C. jejuni infection preceding the
onset of GBS, her symptoms, such as back and abdominal pain, could have been caused by her
preexisting rheumatoid arthritis, peptic ulcer disease, and/or the “long car ride” she underwent just
before her hospitalization, during which she ate at a restaurant. Third Kelkar Rep. at 6-7.
Alternatively, she could have had another type of infection. Id. at 7. He noted that the evidence
as to when Petitioner suffered from “dry heaves” is inconsistent, in that one medical record stated
that occurred one month prior to GBS onset, but another placed that event around the same time
as GBS onset. Id. (citing Ex. 29 at 30, 56). He opined that in any event, this symptom “does not
indicate an active infection of any kind.” Id.

       Dr. Kelkar maintained that the onset of Petitioner’s GBS was about three or four days prior
to her second ER visit on October 31, 2015. Third Kelkar Rep. at 6. This was when her
weakness/motor symptoms began and was an appropriate timeframe for onset of GBS following
vaccination. Id. In a footnote, Dr. Kelkar acknowledged that the medical history pertaining to
onset “is quite confusing.” Id. at 6 n.1. He stated that given the lack of clarity concerning the
timing of Petitioner’s use of prednisone, he focused on weakness as the symptom signifying the
onset of Petitioner’s GBS. Id. He opined that

       [i]f back pain is considered the onset of GBS the shorter timing is supported in the
       literature. If we work backwards from 10/21 and the self-reported use of
       Prednisone for 6 days then off for 3-4 and symptoms got worse, this could mean
       that onset of back pain was within a day or two following the flu vaccination on
       10/21.



                                                 16
Id. He further stated that the medical literature supports a shorter onset period in cases where GBS
is caused by both an infection and vaccination.13 Id. (citing Stratton et al., Adverse Effects of
Vaccines: Evidence & Causality, INST. OF MED. (2012)).14

       G. Dr. Collins’s Third Report

        In her third report, Dr. Collins addressed the timeline of Petitioner’s symptom onset. Ex.
D (“Third Collins Rep.”) at 1. She explained that medical professionals are taught that, where
medical records are not wholly consistent, greater weight should be given to a history that is
obtained directly from the patient close in time to the events being described. Id. Dr. Collins thus
concluded that the October 30, 2015 record from Petitioner’s PCP was the most reliable source of
information about the timeline of events. Id. This record placed the onset of Petitioner’s back
pain “around the same time as vaccination,” which is “too short [a timeframe] to invoke the vaccine
as a cause of her back pain.” Id. at 2.

        Dr. Collins disagreed with Dr. Kelkar’s view that the back pain Petitioner experienced was
not her initial GBS symptom and was instead related to her other medical conditions. Third Collins
Rep. at 2. She also argued that Dr. Kelkar incorrectly minimized Petitioner’s gastrointestinal
symptoms “even though they were a very prominent part of her presentation and the reason she
sought medical attention on October 29.” Id. She commented that, by focusing on Petitioner’s
weakness as the presenting GBS symptom, Dr. Kelkar failed to provide a “compelling explanation
for the abdominal symptoms that brought [Petitioner] to medical attention.” Id.

        Dr. Collins reviewed additional medical literature submitted by Dr. Kelkar relating to the
question of whether flu vaccination can cause GBS. Third Collins Rep. at 3-5. This literature, she
argued, supports the contention that gastrointestinal infection is a much more likely cause of GBS
than vaccination. Id. (citing van den Berg et al., Guillain-Barré syndrome: pathogenesis,
diagnosis, treatment and prognosis, 10 NATURE REVS. NEUROLOGY 469-82 (2014) (Ex. 61) (“van
den Berg”); Willison et al., Guillain-BarrĂ© syndrome, 388 LANCET 717-27 (2016) (Ex. 62)
(“Willison”); Yu et al., Ganglioside Molecular Mimicry and Its Pathological Roles in Guillain-
Barré Syndrome and Related Diseases, 74(12) INFECTION & IMMUNITY 6517-27 (2006) (Ex. 63)
(“Yu”)). She acknowledged that the Fadrique meta-analysis described two studies that found a
very small increased risk of GBS after vaccination. Id. at 4 (citing Fadrique et al., Guillain-Barré
syndrome and influenza vaccines: current evidence, 32(4) OFFICIAL J. SPANISH SOC’Y
CHEMOTHERAPY 288-95 (2019) (Ex. 64) (“Fadrique”)). She noted, however, that “the apparent
small risk observed in some studies was not supported by other observations.” Id. She explained
that “the very small apparent increased risk due to vaccination is confounded by the fact that
influenza vaccination is administered while seasonal influenza is circulating in the population,”
and that “because of these confounding parameters, one cannot be confident of even a minimal
role for the vaccine in causing GBS.” Id. at 5.



 The expert report reads “caused by both an infection and GBS,” which presumably was an error. Third
13

Kelkar Rep. at 6 n.1 (emphasis added).
14
     Petitioner did not file this into the record.
                                                     17
        Dr. Collins next responded to Dr. Kelkar’s opinion that, despite Petitioner’s positive C.
jejuni serology, that infection was not the likely cause of her GBS. Third Collins Rep. at 7. First,
even if the infection were no longer active at the time of her blood test, GBS is a post-infectious
condition, so C. jejuni could have caused it if it occurred within the appropriate timeframe. Id. at
3. Furthermore, it is uncommon to know precisely when a patient was exposed to a wild pathogen.
Id. “What is clear is that [Petitioner] had a gastrointestinal illness prior to the development of
[GBS] along with a test showing prior exposure to a pathogen associated with high risk of
developing [GBS].” Id. at 7. In sum, the medical records and literature support the proposition
that Petitioner’s GBS was caused by C. jejuni or a different intestinal infection. Id.

        Next, Dr. Collins opined that the medical literature Dr. Kelkar submitted does not support
his dual causation theory. Third Collins Rep. at 8. The Westall article, published in 1986, relied
on outdated theories of GBS causation and did not provide any evidence “that the combination of
influenza vaccination plus a gastrointestinal infection accelerate autoimmune disease or GBS.” Id.
(citing Westall). Similarly, none of the other papers cited by Dr. Kelkar even addressed the
question of whether concomitant vaccination and infection could cause GBS, much less concluded
as such. Id. (citing Wirguin, Cusick, Steiner et al., Transient immunosuppression: a bridge
between infection and the atypical autoimmunity of Guillain–BarrĂ© syndrome, 162 CLINICAL AND
EXPERIMENTAL IMMUNOLOGY 32–40 (2010) (Ex. 70) (“Steiner”)).

       Dr. Collins concluded that, if back pain were the first GBS symptom, its onset was too
soon after the subject vaccination to make a causal attribution. Third Collins Rep. at 8.
Alternatively, regardless of whether back pain or weakness were considered the first GBS
symptom, the gastrointestinal illness Petitioner experienced was the more likely cause of her GBS
than was the vaccine. Id. at 8-9.

   H. Dr. Kelkar’s Fourth Report

         The fourth expert report from Dr. Kelkar addressed the questions posed by Special Master
Oler. First, Dr. Kelkar opined that Petitioner’s back pain was not her initial GBS symptom but
was instead “related to her pre-existing history.” Ex. 72 (“Fourth Kelkar Rep.”) at 1. He explained
that Petitioner had experienced previous flares of back pain and had stopped taking her rheumatoid
arthritis medication. Id.

       Second, Dr. Kelkar opined that Petitioner’s October 29, 2015 lumbar CT showed a large
hemangioma at the T12 vertebral body. Fourth Kelkar Rep. at 1. He did not believe this finding
was significant or explained Petitioner’s back pain. Id.

        Third, Dr. Kelkar confirmed that, in his view, Petitioner’s leg tingling and weakness were
the symptoms signifying the onset of GBS. Fourth Kelkar Rep. at 1. These symptoms began six
days after the vaccination. Id.



                                                18
       Fourth, Dr. Kelkar stated that typically, the symptoms of a C. jejuni infection would appear
before the onset of GBS symptoms. Fourth Kelkar Rep. at 2. Neurological symptoms of GBS
following such an infection usually occur 1-3 weeks after the onset of diarrheal illness, with an
incubation period of 2-5 days before symptoms. Thus, the “C. jejuni infection likely predated the
vaccine.” Id. Because Petitioner’s weakness began on about October 27, 2015, “the infection
would have predated the vaccine received on 10/21/15 by 4 days.” Id.

        Fifth, Dr. Kelkar opined that, although Petitioner had a “high” level of C. jejuni antibodies
in her blood, that did “not necessarily lead to the conclusion that she had an active or recent
infection.” Fourth Kelkar Rep. at 3. The testing method used did not distinguish between
antibodies indicating recent/acute infection and those indicating remote exposure. Id. Dr. Kelkar
also opined that Petitioner had AIDP, which is associated with flu vaccination, not axonal GBS,
which is associated with C. jejuni. Id.15

     I. Dr. Collins’s Fourth Report

        Responding to Special Master Oler’s questions, Dr. Collins first opined that “it is more
likely than not that the onset of Petitioner’s back pain on or before October 23 constitutes the onset
of her GBS.” Ex. E (“Fourth Collins Rep.”) at 1. This was based on Petitioner’s self-reported
medical history to Dr. Jefferson on October 31, 2015. Id. The peer-reviewed literature provides
“extensive description of back pain as the presenting symptom of GBS.” Id. For instance, the
Moulin paper stated that moderate to severe pain, including back pain, is “a common and early
symptom of GBS and requires aggressive treatment.” Id. (citing Moulin). That study reported
pain as a symptom in 85.5% of GBS patients. Id. Additionally, Petitioner’s pain was improved
by her use of prednisone; “[a]s prednisone inhibits the immune response and GBS is immune
mediated, a partial response from prednisone therapy is consistent with GBS-induced pain.” Id.

       Second, Dr. Collins agreed that the hemangioma seen on Petitioner’s lumbar CT was not
the cause of her back pain. Fourth Collins Rep. at 2. Most hemangiomas are asymptomatic and
would not cause a sudden onset of pain. Id. Also, Petitioner’s pain resolved without treatment of
the hemangioma. Id.

        Third, Dr. Collins opined that C. jejuni symptoms and GBS symptoms can appear
concurrently. Fourth Collins Rep. at 2 (citing Taylor et al., Sensitivity and specificity of serology
in determining recent acute Campylobacter infection, 34(5) INTERNAL MEDICINE J. 250-58 (2004)
(Ex. E, Tab 4) (“Taylor”)). Studies looking at the onset of GBS following C. jejuni symptoms
have provided “highly variable” results, with a median interval of nine days. Id. at 3 (citing Rees).




15
  Although Dr. Kelkar referenced several papers in his fourth report that were not previously filed,
Petitioner did not file any of them with the report.

                                                 19
       Furthermore, “[i]t takes time following exposure to a pathogen for antibody to become
detectable.” Fourth Collins Rep. at 3. Thus, the fact that Petitioner had detectable C. jejuni
antibodies in her blood during her hospitalization “indicates that her infection was ongoing for
long enough for an immune response to develop and for the antibody levels to be very high.” Id.
Dr. Collins referenced studies on the antibody response to coronavirus infection that showed
detectable IgM antibodies about four days after infection, with the peak level at day 20. Id. (citing
Hou et al., Detection of IgM and IgG antibodies in patients with coronavirus disease 2019, 9(5)
CLINICAL & TRANSLATIONAL IMMUNOLOGY (2020) (Ex. E, Tab 6) (“Hou”); Liu et al., Patterns of
IgG and IgM antibody response in COVID-19 patients, 9(1) EMERGING MICROBES & INFECTIONS
1269-74 (2020) (Ex. E, Tab 7) (“Liu”)). IgG antibodies to coronavirus were detectable about seven
days post-infection and peaked at 25 days. Id. “Given that Ms. Nelson’s antibody levels were
described as ‘markedly elevated[,’] antibody response was more likely than not near its peak on
November 1st when the sample was collected.” Id. Dr. Collins concluded, based on the November
1, 2015 test results, that Petitioner’s exposure to C. jejuni “could have been approximately three
weeks prior to the sample date (approximately October 10th).” Id.

        Lastly, Dr. Collins opined that Petitioner’s November 1, 2015 C. jejuni test result indicated
she had an active infection. Fourth Collins Rep. at 3. A study measuring antibody responses in
C. jejuni patients showed that the peak antibody response was generally three weeks following
infection as defined by symptom development. Id. (citing Taylor). Dr. Collins argued that “high
levels of antibody are indicative of a recent immune response with a peak of antibody production
about three weeks following development of symptoms. Over time, following the peak, the
antibody response typically declines.” Id.

IV.      LEGAL FRAMEWORK

      A. Petitioner’s Burden

        Under the Vaccine Act, a petitioner may prevail in one of two ways. First, a petitioner may
demonstrate that she suffered a “Table” injury—i.e., an injury listed on the Vaccine Injury Table
that occurred within the time period provided in the Table. § 11(c)(1)(C)(i). “In such a case,
causation is presumed.” Capizzano v. Sec’y of Health & Hum. Servs.,
440 F.3d 1317, 1320
(Fed.
Cir. 2006); see § 13(a)(1)(B). Second, where the alleged injury is not listed in the Vaccine Injury
Table, a petitioner may demonstrate that she suffered an “off-Table” injury. § 11(c)(1)(C)(ii).

        For both Table and non-Table claims, Vaccine Program petitioners bear a “preponderance
of the evidence” burden of proof. Section 13(1)(a). That is, a petitioner must offer evidence that
leads the “trier of fact to believe that the existence of a fact is more probable than its nonexistence
before [he] may find in favor of the party who has the burden to persuade the judge of the fact’s
existence.” Moberly v. Sec’y of Health & Hum. Servs.,
592 F.3d 1315, 1324
(Fed. Cir. 2010); see
also Snowbank Enter. v. United States,
6 Cl. Ct. 476, 486
(1984) (mere conjecture or speculation
is insufficient under a preponderance standard). Proof of medical certainty is not required. Bunting
v. Sec’y of Health & Hum. Servs.,
931 F.2d 867, 873
(Fed. Cir. 1991). In particular, a petitioner
must demonstrate that the vaccine was “not only [the] but-for cause of the injury but also a

                                                  20
substantial factor in bringing about the injury.” Moberly,
592 F.3d at 1321
(quoting Shyface v.
Sec’y of Health & Hum. Servs.,
165 F.3d 1344, 1352
(Fed. Cir. 1999)); Pafford v. Sec’y of Health
& Hum. Servs.,
451 F.3d 1352
, 1355 (Fed. Cir. 2006). A petitioner may not receive a Vaccine
Program award based solely on his assertions; rather, the petition must be supported by either
medical records of by the opinion of a competent physician. Section 13(a)(1).

       In attempting to establish entitlement to a Vaccine Program award of compensation for a
non-Table claim, a petitioner must satisfy all three of the elements established by the Federal
Circuit in Althen. Althen requires that petitioner establish by preponderant evidence that the
vaccinations he received caused her injury “by providing: (1) a medical theory causally connecting
the vaccination and the injury; (2) a logical sequence of cause and effect showing that the
vaccination was the reason for the injury; and (3) a showing of a proximate temporal relationship
between vaccination and injury.” Id. at 1278.

        Each of the Althen prongs requires a different showing. Under Althen prong one, petitioners
must provide a “reputable medical theory,” demonstrating that the vaccine received can cause the
type of injury alleged. Pafford, 451 F.3d at 1355-56 (citations omitted). To satisfy this prong, a
petitioner’s theory must be based on a “sound and reliable medical or scientific explanation.”
Knudsen v. Sec’y of Health & Hum. Servs.,
35 F.3d 543, 548
(Fed. Cir. 1994). Such a theory must
only be “legally probable, not medically or scientifically certain.”
Id. at 549
.

        Petitioner may satisfy the first Althen prong without resort to medical literature,
epidemiological studies, demonstration of a specific mechanism, or a generally accepted medical
theory. Andreu v. Sec’y of Health & Hum. Servs.,
569 F.3d 1367, 1378-79
(Fed. Cir. 2009) (citing
Capizzano,
440 F.3d at 1325-26
). Special Masters, despite their expertise, are not empowered by
statute to conclusively resolve what are complex scientific and medical questions, and thus
scientific evidence offered to establish Althen prong one is viewed “not through the lens of the
laboratorian, but instead from the vantage point of the Vaccine Act’s preponderant evidence
standard.”
Id. at 1380
. Accordingly, special masters must take care not to increase the burden
placed on petitioners in offering a scientific theory linking vaccine to injury. Contreras v. Sec’y of
Health & Hum. Servs.,
121 Fed. Cl. 230, 245
(2015) (“[p]lausibility 
 in many cases may be
enough to satisfy Althen prong one” (emphasis in original)), vacated on other grounds,
844 F.3d
1363
(Fed. Cir. 2017). But this does not negate or reduce a petitioner’s ultimate burden to establish
her overall entitlement to damages by preponderant evidence. W.C. v. Sec’y of Health & Hum.
Servs.,
704 F.3d 1352, 1356
(Fed. Cir. 2013) (citations omitted).

        The second Althen prong requires proof of a logical sequence of cause and effect, usually
supported by facts derived from a petitioner’s medical records. Althen, 418 F.3d at 1278; Andreu,
569 F.3d at 1375-77
; Capizzano,
440 F.3d at 1326
(“medical records and medical opinion
testimony are favored in vaccine cases, as treating physicians are likely to be in the best position
to determine whether a ‘logical sequence of cause and effect show[s] that the vaccination was the
reason for the injury’”) (quoting Althen, 418 F.3d at 1280). Medical records are generally viewed
as particularly trustworthy evidence, because they are created contemporaneously with the




                                                 21
treatment of the patient. Cucuras v. Sec’y of Health & Hum. Servs.,
993 F.2d 1525, 1528
(Fed. Cir.
1993).

        However, medical records and/or statements of a treating physician’s views do not per se
bind the special master to adopt the conclusions of such an individual, even if they must be
considered and carefully evaluated. Section 13(b)(1) (providing that “[a]ny such diagnosis,
conclusion, judgment, test result, report, or summary shall not be binding on the special master or
court”); Snyder v. Sec’y of Health & Hum. Servs.,
88 Fed. Cl. 706
, 746 n.67 (2009) (“there is
nothing 
 that mandates that the testimony of a treating physician is sacrosanct -- that it must be
accepted in its entirety and cannot be rebutted”). As with expert testimony offered to establish a
theory of causation, the opinions or diagnoses of treating physicians are only as trustworthy as the
reasonableness of their suppositions or bases. The views of treating physicians should also be
weighed against other, contrary evidence also present in the record -- including conflicting
opinions among such individuals. Hibbard v. Sec’y of Health & Hum. Servs.,
100 Fed. Cl. 742,
749
(2011) (not arbitrary or capricious for special master to weigh competing treating physicians’
conclusions against each other), aff’d,
698 F.3d 1355
(Fed. Cir. 2012); Caves v. Sec’y of Health &
Hum. Servs., No. 06-522V
2011 WL 1935813
at *17 (Fed. Cl. Spec. Mstr. Apr. 29, 2011), mot.
for review den’d,
100 Fed. Cl. 344, 356
(2011), aff’d without op., 475 Fed. App’x 765 (Fed. Cir.
2012).

        The third Althen prong requires establishing a “proximate temporal relationship” between
the vaccination and the injury alleged. Althen, 418 F.3d at 1281. That term has been equated to the
phrase “medically-acceptable temporal relationship.” Id. A petitioner must offer “preponderant
proof that the onset of symptoms occurred within a timeframe which, given the medical
understanding of the disorder’s etiology, it is medically acceptable to infer causation.” de Bazan
v. Sec’y of Health & Hum. Servs.,
539 F.3d 1347, 1352
(Fed. Cir. 2008). The explanation for what
is a medically acceptable timeframe must also coincide with the theory of how the relevant vaccine
can cause an injury (Althen prong one’s requirement).
Id. at 1352
; Shapiro v. Sec’y of Health &
Hum. Servs.,
101 Fed. Cl. 532, 542
(2011), recons. denied after remand on other grounds,
105
Fed. Cl. 353
(2012), aff’d without op.,
503 F. App’x 952
(Fed. Cir. 2013). Koehn v. Sec’y of Health
& Hum. Servs., No. 11-355V,
2013 WL 3214877
(Fed. Cl. Spec. Mstr. May 30, 2013), mot. for
review den’d (Fed. Cl. Dec. 3, 2013), aff’d,
773 F.3d 1239
(Fed. Cir. 2014).

    B. Law Governing Analysis of Fact Evidence

        The process for making factual determinations in Vaccine Program cases begins with
analyzing the medical records, which are required to be filed with the petition. Section 11(c)(2).
The special master is required to consider “all [] relevant medical and scientific evidence contained
in the record,” including “any diagnosis, conclusion, medical judgment, or autopsy or coroner’s
report which is contained in the record regarding the nature, causation, and aggravation of the
petitioner’s illness, disability, injury, condition, or death,” as well as the “results of any diagnostic
or evaluative test which are contained in the record and the summaries and conclusions.” Section
13(b)(1)(A). The special master is then required to weigh the evidence presented, including
contemporaneous medical records and testimony. See Burns v. Sec’y of Health & Hum. Servs.,
3
F.3d 413, 417
(Fed. Cir. 1993) (it is within the special master’s discretion to determine whether to
afford greater weight to contemporaneous medical records than to other evidence, such as oral
                                                   22
testimony surrounding the events in question that was given at a later date, provided that such
determination is evidenced by a rational determination).

         Medical records created contemporaneously with the events they describe are generally
trustworthy because they “contain information supplied to or by health professionals to facilitate
diagnosis and treatment of medical conditions,” where “accuracy has an extra premium.” Kirby v.
Sec’y of Health & Hum. Servs.,
997 F.3d 1378
(Fed. Cir. 2021) citing Cucuras,
993 F.2d at 1528
.
This presumption is based on the linked proposition that (i) sick people visit medical professionals;
(ii) sick people honestly report their health problems to those professionals; and (iii) medical
professionals record what they are told or observe when examining their patients in as accurate a
manner as possible, so that they are aware of enough relevant facts to make appropriate treatment
decisions. Sanchez v. Sec’y of Health & Hum. Servs., No. 11-685V,
2013 WL 1880825
at *2 (Fed.
Cl. Spec. Mstr. Apr. 10, 2013) mot. for rev. denied,
142 Fed. Cl. 247
, 251-52 (2019), vacated on
other grounds and remanded,
809 Fed. Appx. 843
(Fed. Cir. Apr. 7, 2020).

        Accordingly, if the medical records are clear, consistent, and complete, then they should
be afforded substantial weight. Lowrie v. Sec’y of Health & Hum. Servs., No. 03-1585V,
2005 WL
6117475
at *20 (Fed. Cl. Spec. Mstr. Dec. 12, 2005). Indeed, contemporaneous medical records
are generally found to be deserving of greater evidentiary weight than oral testimony -- especially
where such testimony conflicts with the record evidence. Cucuras,
993 F.2d at 1528
; see also
Murphy v. Sec’y of Health & Hum. Servs.,
23 Cl. Ct. 726, 733
(1991), aff’d per curiam,
968 F.2d
1226
(Fed. Cir. 1992), cert. den’d, Murphy v. Sullivan,
506 U.S. 974
(1992) (citing United States
v. U.S. Gypsum Co.,
333 U.S. 364, 396
(1947) (“[i]t has generally been held that oral testimony
which is in conflict with contemporaneous documents is entitled to little evidentiary weight.”)).

        However, there are situations in which compelling oral testimony may be more persuasive
than written records, such as where records are deemed to be incomplete or inaccurate. Campbell
v. Sec’y of Health & Hum. Servs.,
69 Fed. Cl. 775, 779
(2006) (“like any norm based upon common
sense and experience, this rule should not be treated as an absolute and must yield where the factual
predicates for its application are weak or lacking”); Lowrie,
2005 WL 6117475
at *19 (“[w]ritten
records which are, themselves, inconsistent, should be accorded less deference than those which
are internally consistent”) (quoting Murphy,
23 Cl. Ct. at 733
)). Ultimately, a determination
regarding a witness’s credibility is needed when determining the weight that such testimony should
be afforded. Andreu,
569 F.3d at 1379
; Bradley v. Sec’y of Health & Hum. Servs.,
991 F.2d 1570,
1575
(Fed. Cir. 1993).

         When witness testimony is offered to overcome the presumption of accuracy afforded to
contemporaneous medical records, such testimony must be “consistent, clear, cogent and
compelling.” Sanchez,
2013 WL 1880825
at *3 (citing Blutstein v. Sec’y of Health & Hum. Servs.,
No. 90-2808V,
1998 WL 408611
at *5 (Fed. Cl. Spec. Mstr. June 30, 1998)). In determining the
accuracy and completeness of medical records, the Court of Federal Claims has listed four possible
explanations for inconsistencies between contemporaneously created medical records and later
testimony: (1) a person’s failure to recount to the medical professional everything that happened
during the relevant time period; (2) the medical professional’s failure to document everything
reported to her or him; (3) a person’s faulty recollection of the events when presenting testimony;
or (4) a person’s purposeful recounting of symptoms that did not exist. LaLonde v. Sec’y of Health
                                                 23
& Hum. Servs.,
110 Fed. Cl. 184, 203-04
(2013), aff’d,
746 F.3d 1334
(Fed. Cir. 2014). In making
a determination regarding whether to afford greater weight to contemporaneous medical records
or other evidence, such as testimony at hearing, there must be evidence that this decision was the
result of a rational determination. Burns,
3 F.3d at 417
.

   C. Analysis of Expert Testimony

        Establishing a sound and reliable medical theory connecting the vaccine to the injury often
requires a petitioner to present expert testimony in support of his or her claim. Lampe v. Sec’y of
Health & Hum. Servs.,
219 F.3d 1357, 1361
(Fed. Cir. 2000). Vaccine Program expert testimony
is usually evaluated according to the factors for analyzing scientific reliability set forth in Daubert
v. Merrell Dow Pharm., Inc.,
509 U.S. 579, 594-96
(1993). See Cedillo v. Sec’y of Health & Hum.
Servs.,
617 F.3d 1328, 1339
(Fed. Cir. 2010) (citing Terran v. Sec’y of Health & Hum. Servs.,
195
F.3d 1302, 1316
(Fed. Cir. 1999). “The Daubert factors for analyzing the reliability of testimony
are: (1) whether a theory or technique can be (and has been) tested; (2) whether the theory or
technique has been subjected to peer review and publication; (3) whether there is a known or
potential rate of error and whether there are standards for controlling the error; and (4) whether the
theory or technique enjoys general acceptance within a relevant scientific community.” Terran,
195 F.3d at 1316
n.2 (citing Daubert,
509 U.S. at 592-95
).

        The Daubert factors play a slightly different role in Vaccine Program cases than they do
when applied in other federal judicial fora. Daubert factors are employed by judges to exclude
evidence that is unreliable and potentially confusing to a jury. In Vaccine Program cases, these
factors are used in the weighing of the reliability of scientific evidence. Davis v. Sec’y of Health
& Hum. Servs.,
94 Fed. Cl. 53, 66-67
(2010) (“uniquely in this Circuit, the Daubert factors have
been employed also as an acceptable evidentiary-gauging tool with respect to persuasiveness of
expert testimony already admitted”). The flexible use of the Daubert factors to evaluate
persuasiveness and reliability of expert testimony has routinely been upheld. See, e.g., Snyder,
88
Fed. Cl. at 743
. In this matter, (as in numerous other Vaccine Program cases), Daubert has not
been employed at the threshold, to determine what evidence should be admitted, but instead to
determine whether expert testimony offered is reliable and/or persuasive.

         Respondent frequently offers one or more experts of his own in order to rebut a petitioner’s
case. Where both sides offer expert testimony, a special master’s decision may be “based on the
credibility of the experts and the relative persuasiveness of their competing theories.”
Broekelschen v. Sec’y of Health & Hum. Servs.,
618 F.3d 1339, 1347
(Fed. Cir. 2010) (citing
Lampe,
219 F.3d at 1362
). However, nothing requires the acceptance of an expert’s conclusion
“connected to existing data only by the ipse dixit of the expert,” especially if “there is simply too
great an analytical gap between the data and the opinion proffered.” Snyder,
88 Fed. Cl. at 743
(quoting Gen. Elec. Co. v. Joiner,
522 U.S. 136, 146
(1997)). A “special master is entitled to
require some indicia of reliability to support the assertion of the expert witness.” Moberly,
592
F.3d at 1324
. Weighing the relative persuasiveness of competing expert testimony, based on a
particular expert’s credibility, is part of the overall reliability analysis to which special masters
must subject expert testimony in Vaccine Program cases.
Id. at 1325-26
(“[a]ssessments as to the
reliability of expert testimony often turn on credibility determinations”); see also Porter v. Sec’y
of Health & Hum. Servs.,
663 F.3d 1242, 1250
(Fed. Cir. 2011) (“this court has unambiguously
                                                  24
explained that special masters are expected to consider the credibility of expert witnesses in
evaluating petitions for compensation under the Vaccine Act”).

     D. Consideration of Medical Literature

        Finally, although this decision discusses some but not all of the medical literature in detail,
I have reviewed and considered all of the medical records and literature submitted in this matter.
See Moriarty v. Sec’y of Health & Hum. Servs.,
844 F.3d 1322, 1328
(Fed. Cir. 2016) (“We
generally presume that a special master considered the relevant record evidence even though [s]he
does not explicitly reference such evidence in h[er] decision.”); Simanski v. Sec’y of Health &
Hum. Servs.,
115 Fed. Cl. 407, 436
(2014) (“[A] Special Master is ‘not required to discuss every
piece of evidence or testimony in her decision.’” (citation omitted)), aff’d,
601 F. App’x 982
(Fed.
Cir. 2015).

V.      ANALYSIS

     A. Issues Presented

        Petitioner alleges two alternative theories of recovery. First, she alleges she has suffered
the Table injury of GBS following flu vaccination. Motion at 10. Second, if the Table
requirements are not found to be satisfied, Petitioner argues she has established GBS caused-in-
fact by her flu vaccination, meeting the Althen prongs of causation. Id. at 11.

        Respondent does not dispute that Petitioner developed GBS. Instead, he argues that
Petitioner has not proven the Table injury of GBS following flu vaccination, because she did not
establish the onset of her GBS fell within the requisite period after vaccination. Response at 8.
Likewise, he contends that Petitioner has not proven any of the Althen prongs. Id. at 13-20.
Finally, he argues Petitioner’s GBS was more likely caused by C. jejuni infection than by her flu
vaccination. Id. at 20.

     B. Table Claim

         To establish the Table injury of GBS following flu vaccination, Petitioner must
preponderantly prove she developed GBS from three to 42 days after flu vaccination.
42 C.F.R. §
100.3
(a)(XIV)(D). The parties here agree that Petitioner developed GBS. See First Kelkar Rep.
at 3; First Collins Rep. at 12. I agree that this diagnosis is supported by the medical records.

        The operative question for the Table claim, then, is whether the onset of Petitioner’s GBS
occurred within the 3-42-day timeframe following vaccination. That question, in turn, presents
two subsidiary questions. The first is when Petitioner developed various symptoms that potentially
signified the onset of GBS. The second is which of those symptoms were related to GBS, as
opposed to other conditions.

           1. When did potential GBS symptoms begin?

        As described in more detail below, the parties’ experts focused on back pain or weakness
                                                  25
as the symptoms most likely signifying the onset of GBS in Petitioner. Based on my review of the
contemporaneous medical records, as well as Petitioner’s affidavit and supplemental declaration,
I conclude that she developed back pain on or before October 21, 2015. She most likely developed
general weakness on October 27 and leg weakness on October 30.

        Petitioner received the flu vaccination on October 21, 2015, during a visit to podiatrist Dr.
Christina Knutson. Ex. 36 at 138. She saw Dr. Knutson that day for numbness in all of her toes
on both feet.
Id. at 137
. At that visit, she had normal strength but had restricted range of motion
of the midfoot and some pain in the second and third intermetatarsal spaces, which was worse on
the left side.
Id.
Dr. Knutson included peripheral neuropathy on her differential diagnosis,
suggesting a possible neurologic cause of these symptoms.
Id. at 138
. Neither expert in this case,
however, addressed whether the foot symptoms Petitioner reported at that visit might have been
an early sign of GBS.

       Petitioner’s supplemental declaration stated that, to the best of her recollection, she and her
husband drove from Minnesota to Florida beginning six days later, on October 27, 2015. Ex. 71
at 1. They spent the night of October 27 in Georgia and arrived in Florida the night of October 28.
Id.
She first went to the ER early in the morning of October 29, 2015, eight days after the
vaccination. Ex. 29 at 6. She complained of nausea and sharp, non-radiating pain in her left mid-
back, which had begun the previous night, October 28.
Id.
Petitioner saw her PCP, Dr. Jefferson, on October 30, 2015, after being discharged from
the ER. Ex. 21 at 87. She still complained of nausea and abdominal pain.
Id.
At that time, she
expanded on her history, reporting that she had experienced one day of “dry heaves” about one
month earlier.
Id.
Perhaps at odds with this report, she also said that her back pain “was first,”
prompting her to take prednisone for six days, and then “everything seemed to get worse when she
did the prednisone about 4 days later,” leading Dr. Jefferson to suspect an ulcer.
Id.
An exam done at the October 30 visit with Dr. Jefferson showed no signs of balance or gait
problems, cranial nerve problems, paralysis, or other motor dysfunction. Ex. 21 at 92.

        The next day, October 31, 2015, Petitioner was taken back to the hospital by EMS. Ex. 29
at 37. She reported to the paramedics that she had experienced four days of weakness.
Id.
She
also said this weakness had been present “since arriving” in Florida.
Id.
Later on October 31, Petitioner saw Dr. Jefferson again in the hospital. Ex. 29 at 50. He
documented a detailed history.
Id.
Petitioner repeated her story that she had previously taken
prednisone for six days. She also reported that after that period, she stopped taking the prednisone,
and “a couple of days” after that began experiencing abdominal symptoms radiating to the back:

       [L]ooking back at the history before this happened [it] started about a week before,
       she had a day of dry heaves for 24 hours and then it was gone and then it happened
       again a couple of days later and it was more of the acute onset of symptoms at that
       point. O[f] interest, she had been having some back pain prior to that and had
       taken a course of prednisone for 6 days she says and then had stopped it a couple
       of days after that is when she started to get more of the abdominal symptoms
                                                 26
        radiating to the back, thought it could possibly be an ulcer, so yesterday we put her
        on Dexilant twice a day, [C]arafate liquid 4 times a day, ondansetron pills,
        Phenergan as a backup and she was supposed to follow up with this on Monday.
Id.
Petitioner further explained that her leg weakness began after her office visit with Dr.
Jefferson the previous day, October 30. Ex. 29 at 50. After several falls, she “decided it was time
to come into [the ER] to get evaluated.”
Id.
a. Back pain

        I construe the medical records to indicate Petitioner’s back pain likely began no later than
October 21, 2015, the day of the vaccination. On October 30 and 31, 2015, Petitioner twice
reported that, before she first went to the ER on October 29, she took a six-day course of prednisone
for back pain. Ex. 29 at 30, 50. She also added that at least “a couple” days passed after she
finished the prednisone before her acute, radiating abdominal pain began, prompting her to go to
the ER.
Id.
This story puts the onset of back pain at least eight days prior to October 29, or October
21.16

        These accounts are credible for several reasons. First, Petitioner made these reports during
the first days of her treatment, when her recollection would have been clearest. As Dr. Collins
persuasively explained, physicians are trained to give greatest credence to histories taken closest
in time to the events in question and directly from the patient.17 Third Collins Rep. at 1. Second,
the detail about taking the six-day course of prednisone was quite specific, and the fact that
Petitioner repeated it twice adds to its reliability. Third, this story was documented in some detail
by Dr. Jefferson, who evidently believed it to be important to deciphering her condition.

                b. Weakness

      According to the October 31, 2015 EMS record, Petitioner reported four days of
“weakness” prior to making the EMS call. Ex. 29 at 37.18 Later that day, she explained to Dr.



16
  At the October 30 office visit with Dr. Jefferson, Petitioner suggested her symptoms got worse about four
days after the prednisone, but on October 31, she said her acute symptoms began “a couple of days” after
discontinuing prednisone. Ex. 29 at 30, 50. This puts the beginning of the acute symptoms from two to
four days after the six-day course of prednisone, meaning the back pain started at least eight days before
October 29, and perhaps started ten days earlier.
17
  Dr. Kelkar agreed that, based on the records, Petitioner’s back pain “was within a day or two following
the flu vaccination on 10/21.” Third Kelkar Rep. at 6 n.1.
18
  Petitioner also told EMS had felt weakness “since” arriving in Florida. Ex. 29 at 37. As stated above,
Petitioner’s supplemental declaration stated that she arrived in Florida the night of October 28, only three
days before she called EMS. Ex. 71 at 1. The timeline in the declaration was provided nine years after the
                                                    27
Jefferson that she experienced leg weakness beginning after her visit with him the day before,
putting the onset of leg weakness on October 30. Ex. 29 at 50. These accounts were made close
in time to the events in question and probably reflected Petitioner’s clearest and best recollection
of her experience. Third Collins Rep. at 1. Taken together, these reports indicate that more general
symptoms of weakness began on or about October 27 (six days after vaccination), while leg
weakness began October 30 (nine days post-vaccination).

           2. Which symptom(s) signified the onset of GBS?

       The question of which symptom marked the onset of GBS is determinative of Petitioner’s
Table injury claim. If back pain was the first GBS symptom, then the onset of GBS was on the
day of vaccination, not between three to 42 days thereafter, as required by the Table. If weakness
was the first GBS symptom, onset fell within the Table timeframe.

        Dr. Kelkar stated that pain radiating to the back is “extremely common in GBS” and is
often the presenting symptom of the condition. Second Kelkar Rep. at 3. He submitted several
papers supporting this. See Yao at 4 (34.5% of GBS patients reported pain during the acute phase;
low back pain was the second most common area of reported pain); Ruts at 1441 (66% of GBS
patients had pain during the acute phase, and 36% had pain in the two weeks prior to the onset of
weakness; “[l]ow-back or back pain was notably present in the acute phase.”); Moulin at 328
(89.1% of GBS patients described pain during the course of their illness, with a majority of those
patients reporting pain preceding the onset of weakness). Dr. Kelkar did not, however, believe
back pain was the first symptom of Petitioner’s GBS. He opined that Petitioner’s back pain was
instead “related to her pre-existing history.” Fourth Kelkar Rep. at 1. He explained that Petitioner
had experienced previous flares of back pain, for which she had been prescribed steroids.
Id.
Additionally, “[s]omewhere down the line” before her hospitalization she stopped taking her
rheumatoid arthritis medication, methotrexate, suggesting her back pain might have been caused
by a flare-up of her arthritis.
Id.
By contrast, in Dr. Kelkar’s view, Petitioner’s “tingling and
weakness” were “absolutely indicative of onset of GBS.”
Id.
Dr. Kelkar also said that he focused on weakness as the presenting symptom of GBS in
Petitioner’s case because the medical records were “quite confusing” and had “conflicting reports”
concerning her timing and use of prednisone for the back pain. Third Kelkar Rep. at 6 n.1.

       Dr. Collins agreed with Dr. Kelkar that there is “extensive” literature supporting the
proposition that back pain can be the presenting symptom of GBS. Fourth Collins Rep. at 1 (citing
Moulin at 328). She opined that Petitioner’s back pain did, indeed, constitute her first GBS
symptom.
Id.
She noted that Petitioner’s pain seemed to resolve with prednisone, suggesting it
was immune-mediated and “consistent with GBS-induced pain.”
Id.
She also pointed out that the



events, however, and by its own account only stated Petitioner’s best recollection of what happened.
Id.
As such, I credit the story provided to EMS on October 31, 2015.

                                                  28
back pain must have been severe, as it prompted her to take her prescription prednisone for relief.
Third Collins Rep. at 2.

        I find Dr. Collins’s opinion on this question to be more persuasive than Dr. Kelkar’s, and
thus I conclude that Petitioner’s bout of back pain marked the onset of her GBS. Importantly, both
experts agreed that back pain is very common in GBS and is commonly a presenting symptom.
Additionally, I am persuaded by Dr. Collins’s point that Petitioner’s successful use of prednisone
to treat her pain meant (1) it was severe; and (2) it was immune-mediated and responsive to
steroids. Moreover, the records in this case demonstrate that both Petitioner and Dr. Jefferson
viewed the back pain to be the beginning of an acute course of symptoms that eventually required
her to seek emergency care. Petitioner twice reported, and Dr. Jefferson twice recorded, the onset
of back pain, six-day course of prednisone, and subsequent onset of radiating abdominal pain
several days later as a unified history of Petitioner’s present illness. Ex. 29 at 30, 50. Had Dr.
Jefferson considered the back pain to be an entirely distinct problem relating to Petitioner’s pre-
existing issues, he would not have emphasized it as part of the medical history culminating in her
hospitalization.

       Finally, I am not persuaded by Dr. Kelkar’s argument that weakness marked the onset of
GBS because the medical records were unclear about the timing or use of prednisone for back
pain. As noted, the records are actually quite specific about Petitioner’s reported use of prednisone
for six days for back pain, a story she repeated twice in the first days of treatment. It is
unpersuasive to dismiss these accounts as immaterial.

       I therefore conclude that the onset of Petitioner’s GBS was October 21, 2015, the day of
vaccination. Accordingly, she does not meet the criteria for the Table injury of GBS following flu
vaccination, which requires the onset of GBS to fall within three to 42 days after the vaccination.

   C. Causation-In-Fact Claim

         With respect to the causation-in-fact theory, the parties dispute the question posed by
Althen prong one; namely, whether the flu vaccination can cause GBS. See, e.g., First Kelkar Rep.
at 3; First Collins Rep. at 5-6; Third Kelkar Rep. at 5; Third Collins Rep. at 3-5. I need not resolve
that question here, because I conclude Petitioner has failed to satisfy Althen prongs two or three,
requiring denial of her claim.

           1. Althen Prong Two

        Under Althen prong two, Petitioner must establish “a logical sequence of cause and effect
showing that the vaccination was the reason for the injury.” Althen, 418 F.3d at 1278. The
sequence of cause and effect must be “‘logical’ and legally probable, not medically or scientifically
certain.” Andreu,
569 F.3d at 1380
(quoting Knudsen,
35 F.3d at 548-49
). A petitioner is not
required to show “epidemiologic studies, rechallenge, the presence of pathological markers or
genetic disposition, or general acceptance in the scientific or medical communities to establish a


                                                 29
logical sequence of cause and effect.” Capizzano,
440 F.3d at 1325
. Instead, circumstantial
evidence and reliable medical opinions may be sufficient to satisfy the second Althen prong.
Id.
Special masters are expected to consider the views of treating doctors. Capizzano,
440
F.3d at 1326
. Such views are often persuasive because the doctors have direct experience with the
patient whom they are diagnosing -- but they are not necessarily dispositive of the causation
question. See McCulloch v. Sec’y of Health & Hum. Servs., No. 09-293V,
2015 WL 3640610
, at
*20 (Fed. Cl. Spec. Mstr. May 22, 2015).

         Although a petitioner does not bear the burden of eliminating all alternative causes for her
injury, it is appropriate for a special master to consider evidence relating to such alternative causes
in assessing the Althen prongs. Winkler v. Sec’y of Health & Hum. Servs.,
88 F.4th 958
, 963 (Fed.
Cir. 2023); Doe 11 v. Sec’y of Health & Hum. Servs.,
601 F.3d 1349, 1357-58
(Fed. Cir. 2010);
Walther v. Sec’y of Health & Hum. Servs.,
485 F.3d 1146, 1151
(Fed. Cir. 2007).

                 a. Petitioner’s GBS was more likely caused by a C. jejuni infection than her flu
                    vaccination.

        In this case, I am persuaded by Dr. Collins’s opinion that Petitioner’s GBS was likely
caused by a C. jejuni infection, negating a logical connection between the vaccination and her
injury. See First Collins Rep. at 12. As Dr. Kelkar acknowledged, “GBS can be triggered by a
variety of infections and the most common infection is campylobacter jejuni.” First Kelkar Rep.
at 3. Up to 30% of GBS patients are positive for C. jejuni, and one in 1,000 cases of C. jejuni are
estimated to result in GBS.
Id.
(citing Israeli at 122); see also First Collins Rep. at 8 (a history of
C. jejuni infection is reported in 26-60% of GBS cases).

                     1) Petitioner’s test results and clinical presentation were consistent with active
                        or recent C. jejuni infection.

        According to her blood test from November 1, 2015, Petitioner’s blood had a high level of
C. jejuni antibodies. Ex. 29 at 279. The test report explained that a level greater than 1.10 indicated
detection of the antibody; Petitioner had a level of 2.34, which was designated in the report as
“high.”
Id.
The report further explained that “[m]arkedly elevated levels of antibodies recognizing
C. jejuni typically indicate recent or ongoing infection.”
Id.
Despite this result, Dr. Kelkar maintained that it was unlikely Petitioner had a recent or
active C. jejuni infection at the time of her hospitalization. See First Kelkar Rep. at 3. He pointed
out that the blood test did not differentiate among IgM, IgA, and IgG antibodies, and thus he argued
it did not reveal whether Petitioner’s C. jejuni exposure was active, recent, or remote.19
Id.
He
said the “high” designation did not necessarily indicate that she had an active or recent infection.
19
  According to Dr. Kelkar, he learned this information from a discussion with a medical director for Quest,
which generated the report. First Kelkar Rep. at 3. The statements of the Quest representative are hearsay.
Nonetheless, even assuming the truth of the statement that Quest’s test did not differentiate among C. jejuni
antibodies, as discussed, the test report itself supports the conclusion that Petitioner had an acute or recent
infection.

                                                      30
Fourth Kelkar Rep. at 3. But this is contrary to the test report’s characterization of the results.
Moreover, as Dr. Collins pointed out, the Taylor study showed a significant rise in all classes of
C. jejuni antibodies in patients with acute infections compared to controls, with the highest level
at about three weeks post-symptom onset, after which antibody levels began to decline. Fourth
Collins Rep. at 3; Taylor at 254 (Fig. 3). Thus, the “high” level identified in the test was consistent
with acute or recent infection.

        Dr. Kelkar also questioned whether Petitioner had symptoms indicative of an active or
recent C. jejuni infection. Second Kelkar Rep. at 2. He said she did not have diarrhea, a fever, or
an elevated white blood cell (“WBC”) count20 at any time during her course.
Id.
The fact that
Petitioner did not have diarrhea did not rule out C. jejuni. In the Rees study of GBS in C. jejuni-
infected patients, only 19 of 27 patients who tested positive for C. jejuni reported experiencing
diarrhea in the 12 weeks before the onset of GBS. Rees at 1376. Also, the Nandkishor case report
described a case of C. jejuni infection in which the patient did not have diarrhea, nausea, vomiting,
or chills. Nandkishor at 1.

         As Dr. Collins commented, Petitioner had significant gastrointestinal symptoms, including
abdominal pain and “recalcitrant nausea and vomiting,” which prompted her to seek medical
attention on October 29, 2015. Second Collins Rep. at 2-4. A few days later, she was seen in the
hospital by a gastroenterologist for these symptoms. Ex. 29 at 53 (consultation with
gastroenterologist Dr. Dumas). Dr. Kelkar suggested the symptoms might have been caused by
peptic ulcer disease or restaurant food. Third Kelkar Rep. at 6-7. This was not the view of
Petitioner’s treating physicians, however. Although they considered a number of possibilities,
none of them concluded her gastrointestinal symptoms were due to an ulcer or a food-borne illness
other than C. jejuni. After Petitioner was diagnosed with GBS, Dr. Dumas surmised that her
gastrointestinal symptoms were related to that condition, not an ulcer or carcinoma as he originally
considered. Id. at 82. Also, infectious disease specialist Dr. Farooq did not suspect food poisoning
such as botulism explained Petitioner’s presentation; he believed C. jejuni was the only infectious
illness that fit her symptoms. Id. at 65.

                    2) Petitioner’s GBS presentation was consistent with C. jejuni causation.

        Dr. Kelkar did not believe Petitioner’s symptoms were suggestive of the AMAN subtype
of GBS, which is an axonal form of the disease primarily associated with C. jejuni. Second Kelkar
Rep. at 4. Instead, he opined she developed AIDP, a demyelinating form of GBS. Id. He claimed
Petitioner had a faster recovery and a better outcome than would be expected in AMAN. First
Kelkar Rep. at 4.

       Petitioner’s treating physicians did not diagnose her with any particular subtype of GBS.
Dr. Collins persuasively explained that her clinical course fit with C. jejuni causation. See First
Collins Rep. at 11. With respect to her rate of recovery, Chowdhury & Arora noted that the Ho

20
  This is inaccurate. Dr. Jefferson noted on October 31, 2015, that Petitioner’s white blood cell count was
over 14,000 at the time of her admission. Ex. 29 at 50. Petitioner’s hematology results showed high WBCs
of 14,800 on October 31, 2015 and 15,700 on November 1, 2015, with the reference range between 3,600-
11,200. Id. at 244.

                                                    31
study “found a comparable rate of recovery in AMAN and AIDP patients (average 40 days).”
Chowdhury & Arora at 270. The Hiraga study found variability in the recovery rates among
AMAN patients, noting that at least some patients with severe AMAN (as shown by EMG results)
recovered rapidly. Hiraga at 721. Moreover, contrary to Dr. Kelkar’s view, Petitioner’s recovery
was fairly slow. In Hiraga, a “slow” recovery from GBS was defined as being unable to walk
independently six months after onset. Id. at 720. Petitioner met this definition: nearly three years
after the vaccination, neurologist Dr. Ahlskog characterized Petitioner’s recovery as slow and
incomplete, remarking that after her illness she newly required a cane for balance and used a
scooter. Ex. 32 at 212.

         Also, Dr. Kelkar argued that Petitioner’s EMG – taken “one year” after the onset of her
GBS – showed “nearly normal” results, inconsistent with the expected recovery from AMAN.
Second Kelkar Rep. at 5. But in fact, the EMG was performed by Dr. Ahlskog in September 2018,
nearly three years after the vaccination. Ex. 32 at 214. Thus, Dr. Kelkar’s opinion on the import
of this study was unpersuasive.

       Finally, Dr. Collins persuasively pointed out that both AMAN and AIDP are associated
with C. jejuni infection. First Collins Rep. at 11; see Chowdhury & Arora at 270 (“Both axonal
GBS and AIDP cases have been described in association with C. jejuni.”). Thus, regardless of
which subtype Petitioner had, it could have been caused by C. jejuni.

                   3) The onset of Petitioner’s GBS was consistent with C. jejuni causation.

        As discussed above, the records show Petitioner likely developed back pain on or about
October 21, 2015, the day of vaccination. The records indicate she started having gastrointestinal
symptoms about six days later, during her drive to Florida from October 27-28. Ex. 29 at 30. She
told infectious disease specialist Dr. Farooq that the first night of the drive, she had abdominal
pain and nausea, but no diarrhea. Id. at 62. She had to take Pepcid AC during the drive. Id. at 30.
By the time she first presented to the ER on October 29, she was experiencing nausea and sharp,
non-radiating left mid-back pain, for which she had taken oxycodone. Id. at 6. Thus, it appears
that Petitioner’s GBS symptoms predated the onset of her gastrointestinal symptoms.

       However, Dr. Collins persuasively explained that Petitioner’s exposure to C. jejuni
probably predated her development of GBS symptoms. She pointed out that “[u]nlike vaccination
where the date of exposure is precisely known, it is harder to determine when an individual initially
became infected with a pathogen. This is because pathogens have an incubation period following
exposure and prior to symptoms onset that is highly variable.” Fourth Collins Rep. at 2-3. For
example, in the Rees study, while the median interval between the onset of diarrhea and GBS
symptoms was nine days, 30% of the C. jejuni-positive patients who developed GBS did not have
any diarrheal illness preceding onset of their GBS. Id. at 3; see Rees at 1376.

       Dr. Collins further explained that “[i]t takes time following exposure to a pathogen for
antibody to become detectable.” Fourth Collins Rep. at 3. Thus, the result of Petitioner’s
November 1, 2015 blood test “indicates that her infection was ongoing for long enough for an
immune response to develop and for the antibody levels to be very high.” Id. “Given that Ms.
                                                 32
Nelson’s antibody levels were described as ‘markedly elevated[,’] antibody response was more
likely than not near its peak on November 1st when the sample was collected.” Id. Thus,
Petitioner’s exposure to C. jejuni “could have been approximately three weeks prior to the sample
date (approximately October 10th).” Id.

       The literature supports Dr. Collins’s opinion. In the Taylor study, all classes of C. jejuni
antibodies peaked about three weeks after the onset of symptoms. Taylor at 254 (Fig. 3).
Similarly, in Liu, IgM antibodies for Covid-19 peaked 20 days after the onset of symptoms, while
IgG antibodies peaked at day 25. Liu at 2. In Hou, Covid-19 IgM levels peaked at 2-3 weeks after
symptom onset, while IgG antibodies increased more slowly but stayed high for up to seven weeks.
Hou at 5. Collectively, these studies show that exposure to a pathogen will precede the
detectability of high levels of antibodies potentially by several weeks. Based on this, given her
“high” test result on November 1, 2015, Petitioner’s C. jejuni exposure may have occurred as early
as October 10, about 11 days before the onset of back pain on October 21, 2015 (which marked
the beginning of her GBS).

        Notably, Dr. Kelkar agreed that Petitioner’s C. jejuni exposure likely predated the
vaccination. Based on his view that weakness marked the onset of Petitioner’s GBS, he opined
that Petitioner’s C. jejuni exposure likely occurred about 10 days before her weakness began, on
October 17, 2015. Fourth Kelkar Rep. at 2.

                   4) The evidence does not substantiate the claim that Petitioner’s GBS was
                      concurrently caused by the vaccine and C. jejuni infection.

       Dr. Kelkar proposed that the flu vaccine and C. jejuni infection could have acted
synergistically to cause Petitioner’s GBS. First Kelkar Rep. at 3; Third Kelkar Rep. at 8.

        I did not find Dr. Kelkar’s opinion on this question to be persuasive. Aside from the fact
that the onset of Petitioner’s GBS was too soon after the vaccination to implicate it as a causal
factor, which is discussed below, the literature Dr. Kelkar cited did not adequately substantiate his
proposition.

        Dr. Kelkar first cited the Greene study. First Kelkar Rep. at 3. Greene reported on six
cases of GBS following both respiratory infection and flu vaccination. Greene at 1100. The
authors did not attempt to measure or describe a possible synergistic effect of these factors, though
they did mention this possibility. Id. at 1106. Notably, they considered antecedent respiratory
infection a confounding factor in assessing the independent risk of the vaccine for GBS. Id.

        Dr. Kelkar cited the Parra study. Parra reported an association of GBS with Zika virus
infection based on a study done in Colombia. Parra at 1522. Many of the study subjects tested
positive for antibodies indicating past exposure to dengue virus. Id. None of the subjects had
active dengue virus infection. Id. Dr. Kelkar also cited Amereller, a case report of a patient who
had concurrent C. jejuni and Y. pseudotuberculosis infections and developed GBS and mesenteric
lymphadenopathy, as well as recurrent abdominal symptoms. Amereller at 1. These papers

                                                 33
addressed the potential role of concurrent or successive infections in GBS; neither suggests that
GBS can be caused by a synergy between flu vaccine and C. jejuni infection.

       Dr. Kelkar referenced Nachamkin, in which the authors reported the development of anti-
ganglioside antibodies in mice who were immunized with seasonal flu vaccines. Nachamkin at
226. The authors did not comment on whether concurrent C. jejuni infection and flu vaccination
could combine to cause GBS in humans.

       Dr. Kelkar cited Westall, which proposed that post-vaccination neuropathy was caused by
a combination of molecular mimicry and the body’s reaction to vaccine adjuvants. Westall at 251.
As Dr. Collins persuasively noted, this nearly 40-year-old paper was published “well before a
substantive body enlightened our understanding of risk factors associated with [GBS].” Third
Collins Rep. at 8. Moreover, the paper did not hypothesize or present any evidence that the flu
vaccine can combine with C. jejuni to cause GBS.

       Finally, Dr. Kelkar cited Wirguin, Cusick, and Steiner. In Wirguin, rats immunized with
both C. jejuni lipopolysaccharides and keyhole limpet hemocyanin developed high titers of
antiganglioside antibodies. Wirguin at 138. In Cusick, the authors discussed the hypothesis that
the expression of dual T cell receptors on a single T cell could leave the host vulnerable to
autoimmunity. Cusick at 102. In Steiner, the authors proposed that GBS could be caused by
successive infections due to transient immunosuppression. Steiner at 32. None of these studies
discussed a possible synergistic effect produced by flu vaccination and C. jejuni infection.

                   5) Conclusion

        In Winkler, the Federal Circuit affirmed the denial of a petition alleging GBS caused-in-
fact by a tetanus, diphtheria, and acellular pertussis (“Tdap”) vaccination. 88 F.4th at 963. The
special master determined that the petitioner had failed to satisfy Althen prong two, because the
evidence showed he suffered a gastrointestinal illness before the onset of his GBS symptoms. Id.
at 962. The illness was clinically consistent with C. jejuni, but that diagnosis was not confirmed.
Id. The Federal Circuit noted that, even though the Vaccine Act did not require the petitioner to
eliminate all possible alternative causes of the injury, the special master could consider potential
alternative causes in determining whether a logical sequence of cause and effect existed between
the vaccination and the injury. Id. Moreover, the special master was not required to make a
definitive finding that an alternative cause was the more likely cause of the GBS; she could instead
rely on evidence of a possible alternative cause to find Althen prong two unsatisfied. Id. at 963
(citing Stone v. Sec’y of Health & Hum. Servs.,
676 F.3d 1373, 1379
(Fed. Cir. 2012)).

        Similarly, in this case the evidence shows Petitioner likely suffered from a C. jejuni
infection, and that infection was a more likely cause of her GBS than the flu vaccination,
particularly given the same-day onset of GBS symptoms and vaccination. Thus, Althen prong two
is not satisfied here.

               b. The medical records do not show Petitioner’s treating physicians believed her
                  GBS to be vaccine-caused.

                                                34
        Lastly, I did not find persuasive evidence in the medical records that Petitioner’s treating
physicians considered her GBS to be caused by the flu vaccine, though the vaccine was discussed
as a possible cause. The only treating physician who explicitly attributed Petitioner’s GBS to her
flu vaccination was neurologist Dr. Coleman, who summarily characterized her case as “likely
triggered by influenza vaccine,” without further comment and weeks after the onset of Petitioner’s
GBS. Ex. 29 at 135.

        The question of causation was considered primarily by the infectious disease specialist who
saw Petitioner in the hospital several times. The first time that physician saw Petitioner, he or she
noted that she had received the flu vaccine but stated that GBS “has always been a questionable
side effect from flu vaccine.” Ex. 29 at 103. After Petitioner’s positive C. jejuni result came back,
that physician remarked that her GBS could be related to either the flu vaccination or the infection
and that its etiology was unclear. Id. at 120. Despite this equivocation, the physician did attempt
to report Petitioner’s case to VAERS as a vaccine injury. Id. at 114.

        None of the other treating physicians robustly discussed Petitioner’s flu vaccine as a
possible cause of her GBS. Overall, the records do not provide persuasive evidence that the
treating physicians believed Petitioner’s GBS was caused by the vaccine.

       2. Althen Prong Three

        Althen prong three contains two parts. First, a petitioner must establish the “timeframe for
which it is medically acceptable to infer causation,” and second, he must demonstrate that the onset
of the disease occurred in this period. Shapiro,
101 Fed. Cl. at 542-43
. Having decided the onset
of Petitioner’s GBS was October 21, 2015, the day of vaccination, the remaining issue is whether
the same-day onset of GBS symptoms following flu vaccination is medically acceptable.

       Dr. Kelkar opined that, “[i]f back pain is considered the onset of GBS the shorter timing is
supported in the literature.” Third Kelkar Rep. at 6 n.1. Dr. Collins, by contrast, consistently
opined that an onset of GBS less than 48 hours after flu vaccination would be too short to support
vaccine causation. First Collins Rep. at 12; Second Collins Rep. at 1; Third Collins Rep. at 2.

        I am not persuaded by Dr. Kelkar’s opinion on this question. The only study he cited,
Schonberger, did not report any cases of GBS starting the same day as flu vaccination, or even one
or two days post-vaccination. Instead, the study reported some GBS cases occurring in the first
week after flu vaccination, with the peak risk occurring two to three weeks after vaccination.
Schonberger at 112 (Fig. 4). The fact that GBS occurred within a week of vaccination is entirely
consistent with the 3–42-day onset timeframe set forth in the Vaccine Injury Table.
Id.
The
Schonberger study lacks the specificity to adequately support the proposition that onset within less
than three days would be medically acceptable.

        Furthermore, onset of GBS less than three days following vaccination has consistently been
found to be too short in the Vaccine Program. See, e.g., Flowers v. Sec’y of Health & Hum. Servs.,
173 Fed. Cl. 613
(2024) (upholding dismissal of an entire claim where it was determined that onset
of the petitioner's GBS occurred too soon to qualify as on- or off-Table claim (one to two days
following vaccination)); Velasquez v. Sec'y of Health & Hum. Servs., No. 19-1703V,
2024 WL
                                                 35
829599, at *16 (Fed. Cl. Spec. Mstr. Jan. 31, 2024) (finding that a one-day onset of GBS is not
medically acceptable, absent a showing specific to the claimant's circumstances that would justify
stretching the Table timeframe for onset of GBS following receipt of a flu vaccine); Rowan v.
Sec’y of Health & Hum. Servs., No. 17-760V,
2020 WL 2954954
, at *16-19 (Fed. Cl. Spec. Mstr.
Apr. 28, 2020) (finding a GBS onset sooner than three days post vaccination was not scientifically
or medically supported by the record, given that GBS is known to be mediated by antibodies
produced via the adaptive immune system, and this process takes longer than three days to result
in symptoms); Orton v. Sec’y of Health & Hum. Servs., No. 13-631V,
2015 WL 1275459
, at *3-4
(Fed. Cl. Spec. Mstr. Feb. 23, 2015) (finding a one-day onset of GBS following a flu vaccination
was not substantiated by the evidence).21 While I am not bound by other special masters’ findings,
I find the number of decisions concluding this persuasive. 22

VI.     CONCLUSION

       Although I sympathize with Petitioner, after careful review of the record, I conclude that
she has not met her burden to show that she is entitled to compensation under the Vaccine Act.
The petition is therefore dismissed. The clerk shall enter judgment accordingly.23

        IT IS SO ORDERED.

                                                                  s/ Jennifer A. Shah
                                                                  Jennifer A. Shah
                                                                  Special Master




21
  Dr. Kelkar alternatively posited that the concurrent triggers of flu vaccination and infection could cause
a more rapid onset of GBS following such exposures. Third Kelkar Rep. at 6 n.1. He cited the Stratton/IOM
report, but he did not produce it.
Id.
22
  Because Petitioner has not met her prima facie burden demonstrating either a Table injury or causation
in fact, the burden has not shifted to Respondent to demonstrate that Petitioner’s GBS was caused by a
factor unrelated to the subject vaccination (e.g., the C. jejuni infection).
23
  Pursuant to Vaccine Rule 11(a), the parties may expedite entry of judgment by each filing (either jointly
or separately) a notice renouncing their right to seek review.

                                                    36

Case Information

Court
Fed. Cl.
Decision Date
November 3, 2025
Status
Precedential