Facial nerve palsy following the administration of COVID-19 mRNA vaccines: analysis of self-reporting database

Sato, Kenichiro; Mano, Tatsuo; Niimi, Yoshiki; Toda, Tatsushi; Iwata, Atsushi; Iwatsubo, Takeshi

OBJECTIVES: Facial nerve palsy (or Bell's palsy) has rarely been reported following the administration of coronavirus disease 2019 (COVID-19) mRNA vaccines (BNT162b2 and mRNA-1273), which we investigated using large self-reporting data from the United States (Vaccine Adverse Event Reporting System [VAERS]). METHODS: For VAERS reports of individuals who were vaccinated at the age of 18 years or above between January 2010 and April 2021, we conducted a disproportionality analysis that was adjusted for age and sex. RESULTS: The analysis revealed that the adverse events following immunization (AEFI) of facial nerve palsy, after the administration of COVID-19 mRNA vaccines was significantly highly reported both in 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 were comparable levels to that following influenza vaccination reported before the COVID-19 pandemic (ROR 2.04, 95% CI: 1.76 ∼ 2.36). CONCLUSIONS: The current pharmacovigilance study results suggested that the incidence of facial nerve palsy as their non-serious AEFI may be fewer than or equivalent to that of influenza vaccines, which might be informative in the mid of worldwide vaccination promotions but needs to be validated in future observational studies.