Antibody Responses in Rheumatic Disease Patients Following mRNA Vaccination

November 15, 2021

A prospective observational study presented at the American College of Rheumatology’s annual meeting measured the immunogenicity (ability to provoke an immune response) of mRNA vaccines in fully vaccinated rheumatic disease patients. Researchers used the Swiss long-term observational registry to study 441 patients with rheumatoid arthritis, psoriatic arthritis and axial spondyloarthritis. Participants completed an app-based questionnaire and provided self-collected blood samples before being vaccinated as well as at 4, 12, and 24 weeks post-vaccination. Samples were tested for IgG anti-spike (S1) antibodies; these antibodies recognize the SARS-CoV-2 spike protein, the agent which binds to and invades cells to develop a COVID-19 infection.

Antibody levels differed significantly depending on the therapies patients were taking. Patients on TNF inhibitors were observed to produce less anti-S1 antibodies compared to those on DMARD therapy at the 4 and 12 week intervals. This association was more significant in those taking combination therapy. Patients taking rituximab also had a reduced anti-S1 response, as “4/11 of rituximab-treated patients failed to seroconvert after a full mRNA COVID-19 vaccination.” Additionally, preliminary results demonstrated a decline of anti-spike S1 antibodies from weeks 4-12 in those without prior SARS-CoV-2 infection. Further analysis will allow for the assessment of anti-spike S1 responses at the 24 week mark.