Minor pains, including muscle aches and headaches, are usual side effects reported by those who get the COVID-19 vaccine, and many people may think it beneficial to pre-medicate with a pain reliever as a preventative measure prior to vaccination. But experts warn that common over-the-counter pain relievers could interfere with the body’s immune response that triggers protection from illness caused by the novel coronavirus.

According to Dr. Anita Gupta, a professor and anesthesiologist at Johns Hopkins School of Medicine, pain relievers like ibuprofen and aspirin may actually be decreasing the efficacy of the COVID-19 vaccine.

“If you are pre-medicating before a vaccination, you really shouldn’t,” said Gupta. “The reason for that is because these medications can blunt the immune system’s response to the vaccine.”

According to Gupta, common anti-inflammatory drugs including aspirin, ibuprofen, Motrin and Advil block the enzyme known as COX-1, which is the primary enzyme involved in immune response.

Scientists have found that when COX-1 is blocked, it may actually be decreasing the amount of antibodies that the body is producing — the antibodies that are protecting the person’s immune system.

“So when you take the vaccine, you may actually be blunting that response,” Gupta explained. “So, if you can avoid it, you should.”

Gupta’s advice echoes the findings of studies on the effects of anti-inflammatory medications in relation to other vaccines.

One 2009 study out of the Czech Republic found that babies who were given fever-reducing medication prior to immunizations had reduced antibody responses in comparison to the babies with higher post-vaccination fevers.

The study authors noted that medication prior to immunization, “should not be routinely recommended since antibody responses to several vaccine antigens were reduced.”

Gupta noted, however, that if a patient regularly takes pain relievers for a medical condition, especially if they are directed by your physician to do so, they should continue to take the medication.

If you do experience pain or discomfort following the COVID-19 vaccine, the U.S. Centers for Disease Control and Prevention says you can “talk to your doctor about taking an over-the-counter medicine, such as ibuprofen or acetaminophen.”

As current vaccine distributors Pfizer-BioNTech and Moderna increase shipments of vaccinations for Americans, information surrounding a vaccine’s efficacy may be alarming, but Gupta said that it’s still important to get vaccinated.

“These vaccines are very safe, and the evidence shows that over 90 percent people have had benefit from them, from the research that’s been done up to this point,” Gupta said.

“Stay hopeful, get vaccinated, continue to wear masks, social distance, and hand washing, and we’ll get there eventually,” Gupta said.

The Pfizer vaccine showed 95% efficacy at preventing symptomatic COVID-19 infection in its Phase 3 trial, while the Moderna vaccine was found 94.1% effective in preventing the infection.