These Prescription Drugs May Reduce the Efficacy of COVID-19 Vaccines

Millions of Americans take medications that suppress the immune system, and research suggests this could reduce the effectiveness of the COVID-19 vaccines. Rec Visual/Getty Images

Almost 3 percent of insured U.S. adults under the age o…

Millions of Americans take medications that suppress the immune system, and research suggests this could reduce the effectiveness of the COVID-19 vaccines. Rec Visual/Getty Images
  • Almost 3 percent of insured U.S. adults under the age of 65 take medications that suppress the immune system.
  • The prevalence of these medications is a problem because they may reduce the efficacy of COVID-19 vaccinations.
  • Experts suggest we may be able to get around this problem by changing the timing of medications or giving booster shots to these patients.
  • It's a good idea to get vaccinated, however, since the vaccine can still provide some protection.
  • Immunocompromised patients are recommended to continue to follow precautions such as handwashing and physical distancing even after being vaccinated.

Researchers at Michigan Medicine have found that almost 3 percent of insured U.S. adults under age 65 take medications that weaken the immune system.

This is important because taking these medications may increase a person's risk of COVID-19 symptoms and hospitalization if they contract the virus.

There is also growing evidence that these drugs may reduce the efficacy of COVID-19 vaccinations.

What drugs can suppress the immune system?

Lead author Dr. Beth Wallace, a rheumatologist at Michigan Medicine, said that immunosuppressive drugs are usually used to treat conditions where there is an inappropriate immune response that has the potential to damage certain parts of the patient's own body.

Examples of these types of conditions include autoimmune diseases like rheumatoid arthritis and lupus, she said, where the immune system comes to see certain parts of the patient's own body, like the joints, as a threat.

When the patient's immune system begins to attack these body parts, it can cause damage.

Immunosuppressive drugs can be used to curtail this assault on the patient's own tissues.

Wallace said that another case where people might be using immunosuppressive drugs would be upon receiving an organ transplant. In this case, the drugs are used to prevent the immune system from seeing the transplanted organ as an invader and attacking it.

Additionally, certain types of chemotherapy used to kill cancer cells can have a side effect of suppressing the immune system.

Wallace said that most of these immunosuppressive drugs are not used outside of people with these chronic conditions. However, one type of immunosuppressive drug that is very commonly used is steroids.

Steroids include medications such as prednisone and dexamethasone.

These medications may be given in the short-term for conditions such as allergic rashes, bronchitis, and sinus infections.

“This is a problem,” explained Wallace, “because steroids are very immunosuppressive. We’re learning more and more that even short courses and low doses of steroids can increase people’s risk of infections, and can reduce their response to vaccines, like the COVID vaccine.”

How might these drugs reduce vaccine efficacy?

“Vaccines work by teaching your immune system to recognize a specific threat so that it can respond appropriately if it ever sees that threat again,” said Wallace.

However, according to Wallace, immunosuppressive drugs work by reducing the ability of your immune system to recognize and fight off threats.

This suppression is useful in treating autoimmune conditions like rheumatoid arthritis, where an undesirable immune reaction is occurring.

“But immunosuppression also reduces the immune system’s ability to mount a response to things you want it to respond to, like infections and vaccines,” she said.

“We’re starting to realize that people taking immunosuppressive drugs may have a slower, weaker response to COVID vaccination.”

What can we do mitigate this problem?

Experts say there may be strategies we can use to get around the problem presented by immunosuppression.

Wallace suggested that some may be able to pause their medication around the time they get their vaccination or delay an IV infusion until they've had time to mount an immune response to the injection.

Dr. Meghan Baker, a hospital epidemiologist who works with immunocompromised patients at the Dana-Farber Cancer Institute and Brigham and Women’s Hospital, added that if there is flexibility in the timing of immunosuppressive therapies, experts often recommend completing the COVID-19 vaccine series at least 2 weeks before starting the medications.

If this is not possible, however, they recommend that patients speak with their personal physician about the risks versus benefits of delaying therapy.

Wallace further explained that specific recommendations regarding the timing of immune-suppressing medications would have to be tailored to the needs of the individual.

“For example, if someone is on chemotherapy to treat an active cancer, the risk of temporarily stopping that treatment is much different than the risk of stopping a medication that someone’s been on for 10 years to treat their stable rheumatoid arthritis,” Wallace said.

She also pointed out that different immunosuppressive drugs may affect vaccine response differently.

“So, guidelines that make sense for certain conditions or medications, may not be appropriate for others,” she explained.

In addition to making changes in medication timing, Wallace said, “There are also some studies looking at the effect of a ‘booster shot' in this population, an extra dose given several months after the person is first vaccinated.”

Should people using these drugs get vaccinated?

Baker said that, in general, people on immunosuppressive therapies can and should get vaccinated.

“Although the protective effect may vary depending on the underlying condition or the immunosuppressive therapy, most people will get some protection from the vaccine,” Baker said. “It may reduce the chance that they become infected or develop severe illness if infected.”

“Because the vaccine effectiveness may be reduced,” she added, “it is recommended that people who are immunocompromised continue to use precautions to minimize exposure to SARS-CoV-2.”

Precautions recommended by the Centers for Disease Control and Prevention (CDC) include such measures as mask wearing, handwashing, physical distancing, and limiting contact with other people as much as possible.