Questions Surround Rare Development of GBS After COVID Vaccination

June 25, 2021

Recently, reports have been published associating adenovirus vector COVID-19 vaccines and the onset of unusual variants of Guillain-Barré syndrome (GBS). Notably, experts highlight that there have been no findings suggesting COVID vaccines cause GBS. However, the timing of the condition’s onset occurring shortly after vaccination has raised questions among researchers. 

Within the past month, there have been three different reports linking the AstraZeneca and Johnson & Johnson adenovirus vector COVID-19 vaccines to unusual variants of GBS. Two studies published in the Annals of Neurology on June 10, 2021, linked the development of GBS with the AstraZeneca vaccines in Nottingham, England, and Kerala, India, and involved both men and women. Additionally, during a clinical trial, a woman with a history of migraines who had received the Johnson & Johnson vaccine experienced GBS-like symptoms but recovered after being treated for GBS.  

In each study, researchers found the cases to develop in people 10-22 days after their vaccination. This time period coincides with the maximal immune response to the vaccine,  the point at which the vaccine becomes fully effective. Traditional forms of GBS are characterized by muscle weakness and, sometimes, paralysis following infection with a virus or bacteria. Interestingly, reports of facial weakness were less common in these cases when compared to traditional GBS cases.

Cases of GBS have been reported to VAERS after vaccination with Moderna and Pfizer vaccines as well. While rare, reporting adverse events to VAERS notifies the CDC and FDA on which adverse events to investigate further.