A new study in The Lancet Rheumatology examines the strength and duration of SARS-CoV-2 vaccine–induced immunoglobulin-G antibody responses over time for patients with a variety of autoimmune diseases, compared with healthy controls.
The presence of humoral antibodies to SARS-CoV-2 has been shown to correlate with protection against COVID infection. But for patients with immune-mediated inflammatory diseases (IMIDs), host response to COVID infection or to vaccination is affected by the immune dysfunction imposed by the IMID and by the use of immune-modulating drugs to treat it.
This new study finds a weaker – as shown previously – and less sustained immune response to SARS-CoV-2 vaccines in patients with a variety of IMIDs, including rheumatoid arthritis, spondyloarthritis, psoriasis, inflammatory bowel diseases, and other systemic autoimmune diseases such as lupus. It also points toward the possibility of adjusting treatment and vaccination schedules and strategies for these patients based on their antibody levels, among other factors, to preserve best protection against severe COVID.
“It is important to assess immune response in these patients to see if they still have protection against severe COVID infection,” said lead author David Simon, MD, senior clinical scientist in clinical immunology and rheumatology at University Hospital Erlangen (Germany). “We know that antibody response is an immune correlate. Therefore, it is important to see how large and durable the immune response is to the coronavirus vaccine in these IMID patients, and whether specific drugs or therapies have negative effects on their immune response.”
What was studied?
For this large prospective cohort study, researchers registered 5076 coronavirus-vaccinated individuals. They analyzed serum samples obtained between December 15, 2020, and December 1, 2021, from 2,535 patients diagnosed with IMIDs and participating in a prospective coronavirus study program at the Deutsches Zentrum Immuntherapie in Erlangen. The IMID patients had a mean age of 55.0 years, and 58.9% were women.
A healthy control group of 1,198 individuals without IMID who had a mean age of 40.7 years, including 53.8% men, was also recruited for the analysis. All approved coronavirus vaccines were included, following standard vaccination schedules. Antibody response was measured over time by an enzyme-linked immunosorbent assay from 8 weeks after first vaccination to week 40.
Among the findings, the healthy controls had higher postvaccine antibody levels than did those with IMIDs. But the majority of vaccinated patients with IMID were able to build up a humoral immune response to SARS-CoV-2. Patients who were taking B-cell inhibitors like rituximab (Rituxan, Genentech; and biosimilars) and T-cell inhibitors like abatacept (Orencia, Bristol Myers Squibb) for IMIDs had significantly poorer antibody response.
Greater age and the use of combination therapies for IMIDs, compared with monotherapy, further reduced immune response to the vaccine. In terms of vaccination modality, messenger RNA–based vaccines induced higher antibody levels than did vector-based vaccines. The researchers noted that patients with IMID who were given a third vaccine dose could actually catch up well with the antibody responses observed in healthy controls.
“We looked at whether different IMIDs had a different humoral response, and we also assessed if there are effects from different therapeutic strategies,” Dr. Simon explained. “It doesn’t matter so much what kind of IMID patients have; much more important is the specific drug treatment and its impact on their antibody response.” Some participants were advised to briefly stop taking some immunosuppressive treatments before or after vaccination.
One of Dr. Simon’s coauthors, statistician and rheumatologist Koray Tascilar, MD, added, “This research is important because we looked not only at who responded less, which has been previously established, but who are at greater risk of losing their immune response, and how quickly.”