Fever, headache, muscle pain and pain at the injection site remain the most common adverse reactions identified following COVID-19 vaccination. However, cases of myocarditis/pericarditis (inflammation of the heart muscle) and pericarditis (inflammation of the membrane surrounding the heart) following COVID-19 vaccination have been reported. While they can lead to serious illness, they are often mild and respond well to conservative treatment. They have typically occurred within days of vaccination, more commonly among younger males and more often following the second dose of COVID-19 mRNA vaccines. It is important to remember that the frequency of myocarditis/pericarditis following natural infection of SARS-COV-2 is much (about six times) higher than in vaccinated subjects.

To date, due to the limited number of cases as well as their favorable prognosis, the Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency, COVID-19 subcommittee of the WHO Global Advisory Committee on Vaccine Safety (GACVS) and the US Advisory Committee on Immunization Practices (ACIP) have concluded that the benefits of mRNA COVID-19 vaccines in reducing hospitalizations and deaths due to COVID-19 infections continue to outweigh the risks of myocarditis and pericarditis even among young people.

Clinicians should be aware of the rare risk of myocarditis and pericarditis with mRNA vaccines and those most likely to be affected. They should be alert to presentations such as acute chest pain, shortness of breath and palpitations that may be suggestive of myocarditis after vaccination, especially in adolescent or young males. All health professionals are encouraged to report all events of myocarditis and other adverse events observed with these and other vaccines. The GACVS COVID-19 subcommittee will continue to review the safety data from all COVID-19 vaccines and update any advice as necessary.

References:

• COVID-19 subcommittee of the WHO Global Advisory Committee on Vaccine Safety (GACVS): updated guidance regarding myocarditis and pericarditis reported with COVID-19 mRNA vaccines. https://cms.who.int/news/item/09-07-2021-gacvs-guidance-myocarditis-pericarditis-covid-19-mrna-vaccines
• https://www.aemps.gob.es/informa/boletines-aemps/boletin-fv/2021-boletin-fv/6o-informe-de-farmacovigilancia-sobre-vacunas-covid-19/#comirnaty
• https://www.aemps.gob.es/informa/notasinformativas/medicamentosusohumano-3/seguridad-1/2021-seguridad-1/vacunas-frente-a-la-covid-19-actualizacion-sobre-la-evaluacion-de-miocarditis-pericarditis/

Summary:

• Rare cases of myocarditis/pericarditis and pericarditis following COVID-19 vaccination have been reported. They are usually mild and respond well to treatment.
• The reported cases have typically occurred within days of vaccination, more commonly among younger males and more often following the second dose the of COVID-19 mRNA vaccines.
• The benefits of mRNA COVID-19 vaccines in reducing hospitalizations and deaths due to COVID-19 infections continue to outweigh the risks of myocarditis and pericarditis even among young people.