EFFECTS OF VACCINATION AGAINST SARS-COV-2 IN PATIENTS WITH MYASTHENIA GRAVIS IN ECUADOR

Introduction: Safety data on SARS-CoV-2 vaccination in patients with myasthenia gravis (MG) are scarce. Objective: To identify adverse events (AE) after the first and second doses of SARS-CoV-2 vaccination in patients with MG treated at Portoviejo Specialty Hospital, Ecuador. Methods: An observational, descriptive, and retrospective cohort study was conducted in 35 patients with MG. AE were classified as adverse events following immunization (AEFI), severe AEFI, and adverse events of special interest (AESI). Risk differences per 100 persons were calculated between doses. Results: AEFI occurred in 18 patients (51.4%) after the first dose and in 19 patients (54.3%) after the second dose. The most frequent AE were limb pain after the first dose (25.7%) and general discomfort after the second dose (20.0%). No severe AEFI, AESI, hospitalizations, myasthenic crises, or deaths were reported, although most patients received immunosuppressive therapy. The overall risk difference between doses was 0.00 per 100 persons (95%CI: -15.84 - 15.84), with no significant differences in AEFI risk. Conclusion: In this sample of patients with MG, AE following SARS-CoV-2 vaccination were similar to those reported in the general population, and no severe events were observed. These findings should be interpreted with caution because of the observational design and limited sample size; larger studies with longer follow-up are needed.