Question

What reactions have people had to the COVID-19 vaccine?

Answered by infectious diseases expert Mark Rupp, MD

It's common to experience pain at the site of injection, fatigue, headaches, low-grade fevers and body aches. These side effects can last for a few hours up to a few days. These side effects indicate that your immune system is responding and creating immunity to COVID-19.

As of Dec. 19, the Centers for Disease Control and Prevention identified six cases of severe allergy in people who had received the Pfizer vaccine. Most of these people had a history of allergies, and the CDC is following up with one person who didn't have an allergy history. Don't get the COVID-19 vaccine if you're allergic to any of the ingredients in the vaccine, such as polyethylene glycol (a component in some commonly used laxatives). If you have concerns or questions, consult with your primary care physician.

Does the COVID-19 vaccine cause Bell's palsy? Probably not.

During the Pfizer COVID-19 vaccine clinical trials, four people (out of 22,000) developed a case of Bell's palsy. (Bell's palsy is a type of temporary facial paralysis.) That is a 0.018% occurrence rate.

Studies report that Bell's palsy affects 11 to 40 people per 100,000 people each year. That is a normal occurrence rate of 0.011% to 0.040%.

The Bell's palsy occurrence rate among people participating in the Pfizer clinical trial did not exceed the normal occurrence rate seen among the general population.

Because of this, experts determined that the four cases of Bell's palsy were probably unrelated to the COVID-19 vaccine.