Case report: mRNA-1273 COVID-19 vaccine-associated myopericarditis: Successful treatment and re-exposure with colchicine.

Introduction: Vaccine-induced myocarditis is a rare complication of messenger RNA (mRNA) COVID-19 vaccines. Case presentation: We report a case of acute myopericarditis in a recipient of allogeneic hematopoietic cells following the first dose of the mRNA-1273 vaccine and the successful administration of a second and third dose while on prophylactic treatment with colchicine to successfully complete the vaccination. Conclusion: Treatment and prevention of mRNA-vaccine-induced myopericarditis represent a clinical challenge. The use of colchicine is feasible and safe to potentially reduce the risk of this rare but severe complication and allows re-exposure to an mRNA vaccine.

Antibody response to mRNA SARS-CoV-2 vaccination in 182 patients after allogeneic hematopoietic cell transplantation.

INTRODUCTION: Patients after allogeneic stem cell transplantation are at high risk for infection-related complications, and vaccination efficacy might be impaired depending on the immune reconstitution. In this study, we evaluate their response to mRNA vaccines against SARS-CoV-2. METHODS: During routine follow-up visits, patients were asked about their vaccination status and if they had a previous infection with SARS-CoV-2. In fully vaccinated patients, the antibody titer was measured using the Roche Elecsys Anti-SARS-CoV-2 S test. A titer of <1 U/L was considered as negative, titers of ≥250 U/ml as a high antibody titer, and a titer of 50-249 U/ml as a low antibody titer. Patient characteristics were evaluated by chart review to identify risk factors for poor vaccination response. RESULTS: The majority of patients developed a high antibody titer (138 out 182 patients, 75.8%). Risk factors for a low antibody titer were immunosuppressive therapy, a lymphocyte count <0.9 G/L, ongoing treatment for the underlying malignancy, and active graft-versus-host disease (GvHD). Donor type, underlying disease, a previous SARS-CoV-2 infection, and sex did not significantly influence the response to the vaccination. DISCUSSION: While patients undergoing allogeneic stem cell transplantation have been excluded from the initial registration trials, our real-world experience with a large patient cohort confirms the data of previous studies, showing that most patients do have a good response to mRNA vaccines against SARS-CoV-2. Nevertheless, a significant proportion of patients shows an inadequate vaccination, which can be improved after a third vaccination in most cases despite immunosuppressive therapy.