Author Response: Guillain-Barré Syndrome in the Placebo and Active Arms of a COVID-19 Vaccine Clinical Trial.

Abstract

We thank Dr. Willer for his interest in our case report.1 We agree that vaccines can reduce the risk of Guillain-Barré syndrome (GBS) by reducing infection, but this generally assumes that the specific infection that the vaccine targets also increases the risk of GBS.2 However, as mentioned in our article, a large epidemiological-cohort study from Great Britain found no evidence for causality between COVID-19 and GBS.3 A complicating factor is the reduced incidence of GBS during the pandemic that may be attributed to social distancing, wearing masks, and better hygiene. Nonetheless, GBS and COVID-19 incidences vary between regions and do not correlate with one another. These authors also found no evidence of molecular mimicry between any SARS-CoV-2 proteins and human nerve axonal or myelin proteins that might implicate molecular mimicry. Furthermore, not all vaccines cause GBS. Standard epidemiologic methods were used to identify the rare risk of GBS with other vaccines—such as H1N1—and will be needed to ascertain if there is a risk present for the different available COVID-19 vaccinations.