Last week, the FDA's Center for Biologics Evaluation and Research held a meeting to discuss the emergency use authorization of the Pfizer-BioNTech COVID-19 vaccine, including a trial where four cases of Bell's palsy were reported among the vaccinated group and none among the placebo group.
Bell's palsy is a condition that causes weakness or paralysis of the muscles in the face, and is treatable with anti-inflammatory drugs like corticosteroids and, in some severe cases, antiviral therapy. Approximately 80%-90% of patients recover fully within six weeks to three months, with a recurrence rate estimated at 5% to 15%.
According to the study of the vaccine trial, one participant reported Bell's palsy symptoms three days after getting the vaccine, and the symptoms resolved three days later. Three other participants reported symptoms appearing at nine, 37 and 48 days following vaccination and lasted for about 10, 15 and 21 days, respectively. It has also been pointed out that certain conditions can put an individual at a higher risk for developing Bell's palsy, including pregnancy, hypertension, or diabetes.
According to some population studies, Bell's palsy's annual incidence rate within the general population is around 23 cases per 100,000 people or 15-30 per 100,000 people. Compared to the trial, which saw four cases out of 38,000 trial participants, this would translate to 11 cases per 100,000 people.
After looking at the findings, the FDA stated there was "no clear basis upon which to conclude a causal relationship" between the vaccine and the occurrence of Bell's palsy.
Source: USA Today
