Patients With Acute Myocarditis Following mRNA COVID-19 Vaccination
Review of patients referred for CV MRI at a single centre over 3 months (Feb to Apr 2021) found 7 cases of acute myocarditis, 4 of which had occurred within 5 days of COVID-19 vaccination. Authors highlight further investigation is warranted
Source:
JAMA Cardiology
SPS commentary:
A separate report describes a series of 23 cases of acute onset myocarditis following mRNA COVID-19 vaccine in military staff (7 had used the Pfizer and 16 the Moderna vaccine). Authors highlight 2.8 million doses of mRNA COVID-19 vaccine had been given to the military in this time period.
An editorial discusses these findings. It highlights the patients described in these US-based case series had resolution of symptoms or are recovering after receipt of brief supportive care and continue to be monitored during recovery from the acute illness. It states that none of the case series reports are population based and therefore, estimating rates of myocarditis following COVID-19 vaccination is problematic. However, based on data available to date, myocarditis occurring after COVID-19 immunization is rare. The most comprehensive data about the risk of myocarditis following immunization with mRNA vaccines comes from Israel. The Israeli Ministry of Health recently posted data describing 121 myocarditis cases occurring within 30 days of a second dose of mRNA vaccine among 5,049,424 persons, suggesting a crude incidence rate of approximately 24 cases per million following a second dose in this subset of their vaccinated population.
More definitive data on the incidence of myocarditis following immunisation with mRNA COVID-19 vaccines and associated risk will eventually be provided by large population-based vaccine adverse event monitoring systems. But at present the benefits of immunisation in preventing severe morbidity favours continued COVID-19 vaccination, particularly considering the increasing COVID-19 hospitalization rates.
On the 25th June the MHRA issued an alert regarding the Pfizer and Moderna vaccines which advising healthcare professionals to be alert to the signs and symptoms of myocarditis and pericarditis. Vaccinated individuals should be advised to seek immediate medical attention should they experience new onset of chest pain, shortness of breath or symptoms of arrhythmia. This detail has been incorporated into the product SPCs.