Study: Vaccination Against COVID-19 Produces Antibodies in 90% of Patients Taking Immunosuppressants

COVID-19 vaccines produced antibody responses in approximately 90% of individuals with weakened immune systems, according to a study published in Annals of Internal Medicine. The investigators, from Washington University School of Medicine in St. Louis, note that the responses measured were one-third as strong as those mounted by healthy individuals.

“Some of our patients have been hesitant about getting vaccinated, which is unfortunate because they are at increased risk of having more severe cases of COVID-19 if they happen to get infected, compared to those not taking immune suppressing drugs,” said Alfred Kim, MD, PhD, an assistant professor of medicine who treats patients with autoimmune conditions at Barnes-Jewish Hospital, in a press release. “Some of them are worried that vaccination might cause their disease to flare, but we haven’t seen that happen. Others don’t see the point of vaccination, because they think the drugs they’re taking to treat their autoimmune condition will prevent them from producing an immune response to the vaccine. What we found here is that the vast majority of immunocompromised patients with autoimmune diseases are able to mount antibody responses following COVID-19 vaccination. There’s clearly a benefit for this population.”

The study examined individuals taking immunosuppressive medications to treat chronic inflammatory diseases, including inflammatory bowel disease, rheumatoid arthritis, spondyloarthritis, lupus, and multiple sclerosis. The investigators enrolled a participant group comprised of 133 patients and 53 healthy individuals as a control. Each patient was taking at least 1 immune-suppressing medication.

Participants provided blood samples within 2 weeks before receiving their first dose of either the Pfizer or Moderna vaccine, and within 3 weeks after receiving their second dose. Investigators measured each participant’s antibody levels, as well as the number of antibody-producing cells present in their blood samples. All patients remained on their prescribed drug regimens, save for 3 whose medications were paused within 1 week of immunization.

Of the survey participants who were immunosuppressed, 88.7% produced antibodies against SARS-CoV-2, though it was one-third that observed in the healthy control group. A minimum level of antibodies required for protection against COVID-19 has yet to be established, meaning that it is difficult to determine whether the levels achieved by those on immune suppressing drugs are significant enough to protect them from severe COVID-19, according to the investigators. However, the discovery that vaccination does elicit a response in those with compromised immune systems is encouraging for a population who has a high risk of serious illness.

Two drug classes led to particularly weak immune responses, with 65% of patients taking glucocorticoids and 60% of patients taking B cell-depleting therapies developing detectable antibody responses. Participants taking antimetabolites, such as methotrexate, TNF inhibitors, or JAK inhibitors, did not generate significantly weaker immune responses than people not taking those drugs.

The CDC recently recommended third doses for immunocompromised individuals to strengthen their immune responses. The investigators plan to follow this same population following their third dose.

“Nobody knows what minimum level of antibodies is needed for protection,” said Ali Ellebedy, PhD, an associate professor of pathology & immunology, medicine, and molecular microbiology, in the release. “We just don’t know whether people who had low but detectable levels of antibodies are protected or not. It’s that uncertainty that justifies the need for a third dose, especially since we have these highly infectious variants that are capable of causing breakthrough infections even among healthy people.”

REFERENCE

COVID-19 vaccine elicits antibodies in 90% taking immunosuppressants [news release]. EurekAlert; August 30, 2021. Accessed August 31, 2021. https://www.eurekalert.org/news-releases/926886