Facial Nerve Palsy Following the Administration of COVID-19 MRNA Vaccines: Analysis of a Self-reporting Database

Objectives: Facial nerve palsy (or Bell's palsy) has occasionally been reported following the administration of coronavirus disease 2019 (COVID-19) mRNA vaccines (BNT162b2 and mRNA-1273). Our study investigated such cases using a large self-reporting database from the USA (Vaccine Adverse Event Reporting System [VAERS]).

Methods: A disproportionality analysis, adjusted for age and sex, was conducted for VAERS reports from individuals who were vaccinated at the age of 18 years or over, between January 2010 and April 2021.

Results: The analysis revealed that the adverse events following immunization (AEFI) of facial nerve palsy, after administration of COVID-19 mRNA vaccines, was significantly highly reported, both for BNT162b2 (reporting odds ratio [ROR] 1.84; 95% confidence interval [CI] 1.65-2.06) and mRNA-1273 (ROR 1.54; 95% CI 1.39-1.70). These levels were comparable to that following influenza vaccination reported before the COVID-19 pandemic (ROR 2.04; 95% CI 1.76-2.36).

Conclusions: Our pharmacovigilance study results suggest that the incidence of facial nerve palsy as a non-serious AEFI may be lower than, or equivalent to, that for influenza vaccines. This information might be of value in the context of promoting worldwide vaccination, but needs to be validated in future observational studies.