Characterization and Analysis of Neurologic Adverse Events Associated with COVID-19 Vaccination

ABSTRACT

Objective: To characterize the incidence and spectrum of neurological adverse events (AE) after COVID-19 vaccination. Background: The devastating COVID-19 pandemic has led to 230 million people diagnosed and greater than 4.8 million deaths worldwide. Widespread vaccination efforts have resulted in administration of over 6 million vaccine doses to curb the significant health and socioeconomic impacts of the disease. While there are numerous reports of adverse events following COVID-19 vaccine, there is limited characterization of the spectrum of neurological AEs post-vaccination. Design/Methods: Data was gathered from the publicly available Vaccine Adverse Event Reporting System (VAERS), a passive reporting system not implying causality. Among individuals who received the J&J, Moderna, and Pfizer vaccines from 1/1/2021-6/14/2021, 314,610 adverse events were reported and these were reviewed by Neurology trained clinicians to determine the presence of various neurological AEs (40 conditions coded). Results: 306,473,169 COVID vaccine dose were administered in the USA during the study period with 314,610 total AEs (0.10%) and 105,930 neurological AEs (0.03%) reported. J&J vaccine was associated with the most AEs (17,670, 0.15%), followed by Moderna (42656, 0.03%) and Pfizer (42267, 0.03%). On average more events were reported in women (71%) and a majority occurred after the first dose (54%). < 1 events were reported per million vaccine doses for serious neurological conditions such as Bell's palsy (0.0007%), Guillain-Barre syndrome (0.00009%), cerebral venous thrombosis (0.00005%), transverse myelitis (0.00003%), and acute disseminated encephalomyelitis (0.00006%). Overall neurological complications following vaccine were drastically lower than complications post-COVID infection (14-80%). Conclusions: Adverse neurological events following COVID-19 vaccination are extremely rare and significantly less common than adverse neurological effects following SARS-CoV-2 infection. Current evidence suggests that along with being up to 100,000 times more likely to experience a major complication from COVID infection vs. vaccine, the risk of neurological complication is up to 5000 times more likely from infection itself.