In-Depth: Avoid pain relievers before the COVID-19 vaccine, CDC advises

Pain medicines may dampen immune response
FDA: Some pain and fever medications can cause pregnancy complications
Posted at 6:46 PM, Feb 09, 2021
and last updated 2021-04-18 22:56:47-04

SAN DIEGO (KGTV) -- It might be tempting to take Tylenol or Advil before getting a COVID-19 vaccine to stave off the side effects.

However, the Centers for Disease Control and Prevention recommends against it -- at least until there’s more research.

The science is mixed but doctors say there’s a possibility that preemptive pain medicines could dampen someone’s immune response to the vaccine, based on research on mice and previous studies on children.

In the absence of firmer evidence, experts are encouraging people to try other remedies first. They advise people only use pain medicines after the shot if they actually feel side effects like pain, headache or fever that they can’t tolerate.

“If you had a choice, I wouldn’t take it before,” said UC San Francisco infectious disease expert Dr. Peter Chin-Hong. “I would take it after.”

Some over-the-counter pain medicines work by blocking chemicals in your body called prostaglandins. Prostaglandins are hormones that trigger the feeling of flu-like symptoms, so blocking them can offer relief. But the chemicals also have an important role.

They’re like a “bugle horn,” said Dr. Chin-Hong, because prostaglandins summon immune cells.

Taking pain medicines before vaccination could muffle the bugle and result in fewer “troops” -- antibodies -- summoned to the battlefield, he said.

At least that’s the theory, although he notes the science is thin.

One study found mice that were given ibuprofen produced fewer antibodies against the coronavirus. Ibuprofen is the active ingredient in Advil and Motrin.

A 2016 study on children who took pain medication before vaccination found they too produced fewer antibodies. But a larger analysis of several studies found the pain meds didn’t really make a difference.

The Oxford/AstraZeneca clinical trial tested preemptive acetaminophen, the active ingredient in Tylenol, and found it did not substantially affect the immune response, said Dr. Christian Ramers of Family Health Centers of San Diego.

The Oxford vaccine does not use the mRNA technology found in the shots from Pfizer and Moderna.

“The evidence isn't conclusive at this point,” said Dr. Chin-Hong.

He says people should get the shot first, then try simple remedies like a warm towel or arm movement if they feel pain at the injection site. If that doesn’t work, he says it’s ok to reach for the pain meds.

By the time side effects appear after the shot, the immune system is already mobilized. “You’re not going to make it mobilized less,” he said.

Some experts have suggested that people consider acetaminophen for vaccine-related side effects instead of ibuprofen, since ibuprofen affects prostaglandins the most directly.

“Personally, it probably doesn't really matter,” said Dr. Chin-Hong.

Even though the CDC recommends that people avoid pain medicines before getting the vaccine, doctors say people who regularly take the drugs for chronic conditions like inflammatory diseases or arthritis should stick to their regular routine.