FDA staff recommend watching for Bell’s palsy in recipients of Moderna and Pfizer vaccines

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The U.S. Food and Drug Administration staff recommend monitoring people who receive Pfizer or Moderna’s Covid-19 vaccine shots for possible cases of Bell’s palsy, and say it’s not necessarily a side effect, but worth noting. After a handful of test participants got the condition, watch that half of your face droop.

A 54-page staff report released Tuesday said there were four cases of Bell’s palsy among the more than 30,000 participants in Moderna’s clinical trial. Three of the participants who got Bell’s palsy also received the vaccine instead of a placebo injection. Pfizer’s trial had similarly reported four cases of Bell’s palsy in approximately 43,000 participants. All four cases of Bell’s palsy in Pfizer’s study received the vaccine and not the placebo.

The staff, who approved the emergency use of Moderna’s coronavirus vaccine, said there was not enough data to link the cases directly to the recordings, but it warranted close scrutiny. Two of the cases of Bell’s palsy among Moderna’s vaccine group have since been “resolved,” while one was still ongoing at the time of the report, FDA staff said.

Bell’s palsy causes a sudden frostbite or weakness in a person’s facial muscles that is temporary for most people, according to the Mayo Clinic. The exact cause isn’t known, but it’s believed to be from a viral infection, or swelling and inflammation of the nerve that controls the muscles on one side of your face, the Mayo Clinic said.

“Currently available information is insufficient to establish a causal relationship to the vaccine,” wrote FDA staff.

The FDA’s Advisory Committee on Vaccines and Related Biological Products will meet on Thursday to review Moderna’s vaccine. It approved Pfizer’s vaccine a week ago, before the FDA gave formal approval on Friday to begin distribution. Health workers lined up at US sites Monday to receive some of the first injections of Pfizer’s vaccine.

Dr. Paul Offit, a voting member of the FDA’s Vaccines and Related Biological Products Advisory Committee, agreed that the condition is worth monitoring while the vaccine is being rolled out. He voted to recommend Pfizer’s vaccine last week.

“I’m not rejecting that just yet,” he said in an interview with CNBC.

When Merck presented his data from his trial with the rotavirus vaccine, there were five cases of Kawasaki disease, but none in the placebo group. That was “statistically significant” and caused Merck to change its label to record the cases.

Although there was a small imbalance in the vaccine group compared to the placebo, the FDA said it is uncertain whether the drug contributed to the paralysis “because the number of cases was small and no more frequent than expected in the general population.”

“There were no other notable patterns or numerical imbalances between treatment groups for specific categories of adverse events, including other neurological, neuro-inflammatory and thrombotic events, suggesting a causal relationship with the Moderna COVID-19 vaccine,” wrote FDA staff. in the documents.

The FDA guidelines issued Tuesday for Moderna’s vaccine were similar to last week’s recommendations for Pfizer’s vaccine. U.S. Centers for Disease Control and Prevention officials said Pfizer’s vaccine does not appear to cause the condition.

– CNBCs Berkeley Lovelace Jr. contributed to this report.

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