As more people receive the COVID-19 vaccine, one question keeps getting asked: “Can I take pain medication before or after getting the vaccine?”

It is a question many are asking because the vaccine can cause some side effects, such as aches and a low-grade fever. Some may be tempted to take over-the-counter pain relievers before or after getting vaccinated.

But medical experts say that this should be avoided.

“There is a theory that is based in science that some of these medications may interfere with that initial immune response,” Dr. Shereef Elnahal, president and CEO of University Hospital in Newark. “The mechanism of action of these medications is to reduce inflammation. And part of your immune response is actually revving up inflammation to be able to learn what the virus looks like to be able to fight it.”

This is not a new concept. The COVID vaccine is so new that there is not a lot of data surrounding it yet. But researchers have found that giving children Tylenol before childhood vaccinations “significantly reduced fever.” But it also “blunted the immune response” the vaccine was designed to provide.

Doctors say that taking pain medications before receiving the vaccine is not advised. But what about after?

“Nobody really knows. I’m telling my patients if they don’t have to take anything, don’t,” says Dr. Barron Lerner, a professor at the Grossman School of Medicine at NYC. “On the other hand, there’s no real data to suggest that taking something after the shot is really going to diminish the effectiveness of the vaccine.”

Lerner says that one dose of pain medication after receiving the vaccine shouldn’t impact its effectiveness.