Effect of immunomodulatory agents on the response to COVID-19 vaccination among patients with neuromuscular diseases: A single center experience

Immunomodulatory agents, commonly used in autoimmune neuromuscular disorders, may significantly attenuate immunological response to vaccines. Yet, the degree to which different classes of these drugs suppress the immune system is unclear. This study aimed to characterize the response to the coronavirus disease 2019 (COVID-19) vaccines among our cohort of patients with neuromuscular diseases, including both patients who are and are not receiving immunomodulatory agents. This was a retrospective chart review of our single-center neuromuscular clinic patients who had undergone semi-quantitative COVID-19 antibody testing. A sum of 111 patients were initially identified, and 44 were excluded because of various reasons (e.g., COVID-19 infection, etc). The remaining 67 patients had undergone antibody testing after receiving one of the FDA-approved COVID-19 vaccines (2 doses of Moderna or Pfizer/BioNTech, or 1 of Janssen). A sum of 52 of these patients were receiving immunomodulatory treatments, and 15 were not. Patients were grouped based on their relative antibody response to vaccination, and the antibody responses of patients on each of the different immunomodulatory treatments were compared to those of patients not on any immunomodulation. Patients receiving B-cell depleting therapies demonstrated the weakest response to vaccination (P = .002), and those on mycophenolate mofetil also displayed a weaker response compared to patients not on immunomodulation (P = .045). Corticosteroids (P = .584) and intravenous immunoglobulin (P = .941) had minimal effect on COVID-19 antibody response. The degree to which a specific agent may affect a patient's immune response to vaccines or infections may play a role in a clinician's choice of treatment.