Science News: Immune Response and Safety of SARS-CoV-2 mRNA-1273 Vaccine in Patients With Myasthenia Gravis

Submitted by: Nakul Katyal, MD
Edited by: Eman Tawfik, MD                              

Reyes-Leiva D, López-Contreras J, Moga E, et al. Immune response and safety of Sars-Cov-2 Mrna-1273 vaccine in patients with myasthenia gravis. Neurol Neuroimmunol Neuroinflamm. 2022;9(4):e200002. Published 2022 Jun 21. doi:10.1212/NXI.0000000000200002

Summary: This prospective study investigated the safety profile of mRNA-1273 vaccine and its ability to induce humoral and cellular responses in patients with myasthenia gravis (MG).

The study included 100 unvaccinated patients with stable MG scheduled for mRNA-1273 vaccine during the vaccine campaign from April to November 2021. Patients with significant clinical or therapeutic changes in the previous 6 months were excluded. The primary outcomes were clinically significant changes in MG symptoms after vaccination, adverse events (AEs), and seroconversion and T-cell immune response rates. The MG activities of daily life (MG-ADL) score was recorded at baseline and 1 week after the first and second doses. Humoral and cellular immune responses after vaccination were assessed using a spike-antibody ELISA and interferon gamma release assay in plasma.

Ninety-nine patients completed the full vaccination schedule, and 98 had 2 blood samples taken. A statistically significant worsening of symptoms was identified after the first and second doses of the mRNA-1273 vaccine, but this was not clinically relevant and was self-limited (Mean MG-ADL at baseline 2.34 (3.22), 1 week post first dose: 2.65 (3.52), 1 week post second dose: 2.72 (3.57; n= 99). Mild AEs occurred in 14 patients after the first dose and in 21 patients after the second dose. Eighty-seven patients developed a humoral response, and 72 patients showed a T-cell response after vaccination. A combined therapy with prednisone and other immunosuppressive drugs correlated with a lower seroconversion ratio and a lower T-cell response ratio.

Comments: Evidence regarding the safety and efficacy of mRNA vaccines in patients with MG after immunosuppressive therapies is limited. Physicians often come across the question of COVID vaccine’s safety in patients with MG and its efficacy in patients with autoimmune disease taking immunosuppressive therapies. This article provides a class IV evidence regarding safety of mRNA-1273 vaccination in patients with MG. The majority of the patients achieved high cellular or immune response levels. The main study limitations are the lack of a control group and the exclusion of patients with recent clinical or therapeutic changes.