This Medication Could Cause Lower Antibodies After Your Vaccine, Study Says
Researchers suggest alternative vaccination strategies for people on this type of medicine.
The question anyone who's gotten vaccinated against COVID likely has is, "Did it work?" While the vaccines are highly effective at preventing you from getting sick from SARS-CoV-2, the shots—much like the virus itself—don't affect everyone the same way, leaving many of us wondering. But whether you had strong vaccine side effects or not, experts have said anyone who's gotten their COVID shot or shots should know they're protected against the virus. However, according to new research, it turns out that those who take a certain medication may not have a strong enough response from their COVID vaccine.
A new study out of New York University found that people who take methotrexate, a common anti-inflammatory medication for autoimmune disorders, tend to produce fewer antibodies after the vaccine, a key indicator of immunity levels. (The vaccine works by triggering the production of antibodies that are then able to target, disable, and tag the virus for removal from the body.) According to the May 25 study, which was published in the medical journal Annals of Rheumatic Diseases, one in four people who take methotrexate mount a weaker immune response to the COVID vaccine. The study specifically looked at people who received two doses of the Pfizer vaccine who were also taking methotrexate to treat common autoimmune disorders, including rheumatoid arthritis, psoriatic arthritis, and psoriasis.
Researchers found that 90 percent of people not on the medication had strong antibody responses. On the other hand, only 62 percent of people taking methotrexate—which is sold as Rheumatrex, Trexall, Otrexup, and Rasuvo—were able to mount an adequate response. That could leave nearly 40 percent of those on the medication still vulnerable to COVID after their vaccine.
However, researchers are not yet sure what this means for protection. Rebecca Haberman, MD, co-author of the study, said in a statement that a lower antibody response doesn't necessarily mean you're not protected against the virus. "It is most important to state that patients should not be concerned about our study findings as the majority of patients with immune system disorders are responding well to the mRNA vaccines," said Haberman. She noted that "it is also possible that methotrexate is delaying, rather than preventing, an adequate immune response against COVID-19."
Other researchers have found that antibody responses from the COVID vaccine have been thwarted by multiple autoimmune disorder medications. Another study, published in May in the journal Annals of the Rheumatic Diseases, showed that, among people with autoimmune disorders, patients who take either methotrexate and rituximab (Rituxan) respond especially poorly to the COVID vaccine, WebMD reports. That's because these medications suppress the immune system so that the disorders, which cause patients' immune systems to be overactive, are kept under control.
On top of that, a pre-print of a study shared on medRxiv in March found that regular infusions of infliximab (Remicade) can make the first dose of the Pfizer vaccine less effective. Remicade is a common treatment used to address a variety of chronic inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, plaque psoriasis, and ulcerative colitis. The study, which has not yet been peer-reviewed, found that many patients on infiliximab eventually produced an adequate immune response after their second vaccine dose, but some never achieved sufficient immunity.
Researchers involved in the most recent NYU study say alternative vaccine strategies should be considered for those who have a diminished antibody response. In a statement, Jose U. Scher, MD, co-author of the study, included potentially discontinuing or altering the dosage of methotrexate when the vaccine is given or administering a booster shot. While Scher noted that a lower antibody count "may not necessarily mean that the vaccine is not efficacious," he feels "alternate vaccine strategies need to be investigated."