This case report describes a woman who developed Guillain-Barre syndrome (GBS) after receiving the first dose of an mRNA COVID-19 vaccine. Tests showed she had antibodies to the SARS-CoV-2 spike protein from the vaccine but not to the nucleocapsid protein, indicating her GBS was likely precipitated by the vaccine rather than a natural COVID-19 infection. While COVID-19 and vaccines can both potentially cause GBS via molecular mimicry, the report concludes that vaccine benefits outweigh this rare risk and the case helps elucidate mechanisms of adverse vaccine reactions.

1. A Case Report Analyzing Guillain-Barre
Syndrome in COVID:
Differentiating Vaccine Reaction from a
Natural Infection
James T. Johnson, OMS 4

2. Background
• Nearly 750,000 Americans have died from COVID though September, 20211 and
the Moderna and Pfizer mRNA vaccines have been widely given.
• There is emerging evidence of possible association between COVID and Guillain-
Barre Syndrome (GBS).
• GBS varies in severity, often causing a lack of deep tendon reflexes and
sometimes worsening to bulbar dysfunction and respiratory dysfunction.
• In these later stages supportive care is required, and mechanical ventilation can
become necessary.

3. Objective
• This case recounts the clinical course of an individual who developed GBS soon
after SARS-CoV-2 vaccination, and the process utilized to rule out potential
precipitating factors.

4. Case Summary
• A 39-year-old woman presented to the ED with progressive weakness and
paresthesia for three days.
• The patient initially declined admission but over the next two days her weakness
worsened and she had several falls, along with new pain in her lower back.
• At the time of admission, she had no shortness of breath and she denied any
history of neurologic disorders.

5. Case Summary
• CSF was positive for cytoalbuminologic dissociation and neurologic exam was
notable for grade 4 weakness of the lower extremities that was symmetrical with
areflexia.
• She also had decreased sensation distributed up to approximately the T4 spinal
level. An MRI showed no spinal lesion.

6. Case Summary
• Despite therapy with a five-day course of IV immunoglobulins, she became
progressively weaker, had difficulty swallowing and increasing distribution of her
paresthesia.
• By day 6 she was intubated and on day 16 she lacked all motor and sensory
function except for severe neuropathic back pain. She was only able to
communicate through subtle head movements.
• She received a tracheostomy and gastrostomy tube on day 28 and was switched
to mechanical ventilation. She remains on ventilation at the time of writing this
case.

7. Discussion
• The patient had received her first dose of an mRNA SARS-CoV-2 vaccine
approximately 24 days before the onset of her symptoms but had close contact
with several family members who had COVID. We considered the possibility that
she caught COVID despite having been vaccinated.
• SARS-CoV-2 is comprised of four major proteins, forming a nucleocapsid, a spike,
a membrane, and an envelope5. A SARS-2-CoV spike IgG assay and an IgM assay
were used to evaluate her seroconversion status, and both were positive.

8. Discussion
• While this confirmed that she had been exposed to SARS-CoV-2 antigens, it was
still uncertain whether this represented a natural infection or a vaccine response.
• A spike IgG assay was repeated with concomitant nucleocapsid antibody testing.
The patient demonstrated positive spike IgG with no evidence of any
nucleocapsid antibodies
• This suggests that the antigen source was indeed from vaccination and that she
had never had an infection.

10. Conclusions
• There is currently ongoing investigation whether COVID may be a potential
precipitant of GBS but many other sources have been documented. The
most well-known infectious cause is the gastrointestinal bacteria C. Jejuni.
• The prevailing theory underlying GBS pathophysiology is that molecular
mimicry causes autoimmune cross reactivity7.
• Vaccine antigens could plausibly have the same effect as vaccine efficacy
depends entirely upon molecular mimicry.

11. Conclusions
• The preponderance of evidence strongly suggests that the reduction of
morbidity and mortality resultant from SARS-CoV-2 vaccination greatly
outweighs this potential adverse effect.
• The purpose of this discussion is to help elucidate the mechanisms
underlying a specific and rare adverse reaction rather than comment on the
risks vs. the benefits of SARS-Cov-2 vaccination..

12. References
• CDC COVID Data Tracker. (n.d.). Retrieved March 14, 2021, from
https://covid.cdc.gov/covid-data-tracker/#cases_casesper100klast7days
• Caress JB;Castoro RJ;Simmons Z;Scelsa SN;Lewis RA;Ahlawat
A;Narayanaswami P; (n.d.). Covid-19-associated Guillain-Barré Syndrome:
The early pandemic experience. Muscle & Nerve. Retrieved October 18,
2021, from https://pubmed.ncbi.nlm.nih.gov/32678460/.
• Kuwabara, S. (2004). Guillain-barré syndrome: Epidemiology,
pathophysiology and management. Retrieved March 14, 2021, from
https://pubmed.ncbi.nlm.nih.gov/15018590/

13. Disclosures
• This case report was developed using materials provided by Alex Han, MD and
Daniel Santone, MD