Retrospective study on the safety of COVID-19 vaccination in myasthenia gravis

Given the lack of information on safety of coronavirus disease 2019 (COVID-19) vaccination in myasthenia gravis (MG) patients, we aimed to review our experience after surveying patients, as part of routine clinical practice, to ensure that advice on safety is accurate.

We performed a retrospective chart review of MG patients from the Prosserman Family Neuromuscular Clinic at the Toronto General Hospital who received two injections of any COVID-19 vaccine from February to August 2021. Demographic data were abstracted from the patient medical records. We assessed changes in the severity of MG using the virtual Myasthenia Gravis Impairment Index (vMGII), the simple single question (SSQ), and Patient Acceptable Symptom State (PASS). We also assessed adverse effects after vaccination.

We included 200 patients with a mean age of 64.3 ± 13.9 y, 51.5% were men, and 82% had generalized MG. The vMGII, SSQ, and PASS scores remained stable after each vaccine dose, and at last follow-up. Of the patients, 60% reported an adverse reaction after the first injection, and 56% after the second. The most common adverse reactions reported were local pain at the injection site, fatigue, headache, and fever.

COVID-19 vaccinations were well tolerated in MG patients and were not associated with worsening severity of their MG. The prevalence of vaccine-related adverse reactions was the same as in the general population.