Note: an update to this statement is available HERE.
The American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) has reviewed the data submitted to the U.S. Food and Drug Administration (FDA) related to the recently approved COVID-19 vaccines from Pfizer-BioNTech and Moderna that reported four and three cases of facial paralysis (Bell’s palsy) respectively in patients who were vaccinated and one patient who received the placebo.
|Moderna||Facial paralysis and/or Bell's palsy||Onset after injection (days)|
|vaccine n=15,185||3 cases||22, 28, 32*|
|placebo n=15,166||1 case||17|
|Pfizer-BioTech||Facial paralysis and/or Bell's palsy||Onset after injection (days)|
|vaccine n=18,801||4 cases||3, 9, 37, 48|
|placebo n=18,785||0 cases||-|
*One incidence of facial paralysis was from a stroke and would not be typically classified as idiopathic facial paralysis (Bell’s palsy).
Normal background incidence of idiopathic facial paralysis is around 15-30 per 100,000. Using the above data for those who received either vaccine, the equivalent combined incidence of idiopathic facial paralysis is 17.7 per 100,000. While there appears to be a greater number of individuals who developed facial paralysis in the vaccine group, it does not appear to be greater than the expected background rate. Thus, there is no clear basis upon which to conclude a causal relationship at this time. The FDA will continue surveillance for cases of Bell’s palsy with deployment of the vaccine into larger populations.
AAO-HNS feels these rare events should not dissuade healthcare personnel or patients from receiving these critical vaccines. The U.S. Centers for Disease Control and Prevention (CDC) and FDA are mounting an incredibly robust effort to transparently monitor safety. For vaccinated individuals wishing to report side effects after getting the COVID-19 vaccine, the CDC is providing a smartphone-based tool for feedback.