Associations of neuralgic amyotrophy with COVID‐19 vaccination: Disproportionality analysis using the World Health Organization pharmacovigilance database

Introduction/Aims There are limited studies on the association of COVID‐19 vaccination with neuralgic amyotrophy (NA). Therefore, we evaluated the association between COVID‐19 vaccination and the occurrence of NA. Methods We explored unexpected safety signals for NA related to COVID‐19 vaccination through disproportionality analysis using VigiBase, the World Health Organization's pharmacovigilance database. Results On October 15, 2021, 335 cases of NA were identified in the database. The median time to onset of NA after vaccination was around 2 weeks. A significant signal of disproportionality of NA was observed for the ChAdOx1 nCoV‐19 vaccine (AstraZeneca) (information component [IC] 025 = 0.33, reporting odds ratio [ROR] 025 = 1.30) and two mRNA‐based COVID‐19 vaccines (BNT162b2 [Pfizer and BioNTech] and mRNA‐1273 [Moderna]) (IC 025 = 1.74, ROR 025 = 3.82) compared with the entire database. However, when compared with influenza vaccines, we did not detect any signal of disproportionality of NA for both the ChAdOx1 nCoV‐19 vaccine (IC 025 = −2.71, ROR 025 = 0.05) and mRNA‐based COVID‐19 vaccines (IC 025 = −1.38, ROR 025 = 0.13). Discussion A weak association was observed between NA and COVID‐19 vaccines. However, the risk did not surpass that of influenza vaccines.