An elevated rate of Bell’s palsy (BP), a condition characterized by facial paralysis or weakness, was identified among elderly individuals who received a booster shot of Pfizer’s COVID-19 vaccine, according to a preprint study by researchers at the U.S. Food and Drug Administration (FDA).
The study found a “small but statistically significant elevation” in the incidence of BP among those who received the booster shot, with an adjusted incidence rate ratio of 1.13, a rate above one being considered indicative of a potential association between the vaccine and an adverse event.
“A small but statistically significant elevation in BP risk was detected following a booster dose of BNT162b2 vaccination (IRR: 1.13, 95% CI: 1.03 to 1.25), and it remained consistent across additional analyses such as adjustment for seasonality and prior COVID-19 infection exclusion (IRR: 1.17, 95% CI: 1.06 to 1.29),” the study reads.
The elevated rate remained consistent even when researchers adjusted for different factors, such as prior COVID infection.
The FDA also found a “small but statistically significant elevation in risk” of acute myocardial infarction (AMI), also known as a heart attack, following both primary vaccinations with Pfizer’s mRNA jab as well as booster doses. However, “this effect was no longer statistically significant when accounting for seasonality, adjusting for outcome misclassification using MRR-derived PPVs, and excluding individuals with prior COVID-19 infection (IRR=1.04, 95% CI: 0.91 to 1.18),” the study authors write.
The agency moreover “detected a small but statistically significant elevated risk” of pulmonary embolism (PE)—a serious medical condition that occurs when a blood clot forms in a vein and travels through the bloodstream to the lungs—among those who received a primary Pfizer vaccine dose. The risk “remained significant in analyses adjusting for seasonality and PPV, and excluding individuals with prior COVID-19 infection,” according to the FDA study.
