Myocarditis and COVID-19: for some people the risk may be higher following vaccination than infection

COVID-19 is a known cause of cardiac complications such as myocarditis and systolic dysfunction. Vaccine associated myocarditis was described following smallpox vaccination, streptococcal pneumonia and influenza vaccine. In some cases, autoimmune/inflammatory syndrome induced by adjuvants used in the vaccine have been also implicated. 

Associations of COVID-19 vaccination and myocarditis have been proposed in multiple publications, but the consensus was that the benefits of vaccine are worth the increased risk even though more personalized approach seems warranted by the evidence.

A new study presents data about the risk of myocarditis increasing with each subsequent dose of mRNA vaccines, especially mRNA-1273. Moreover, in younger males the risk of myocarditis was higher following vaccination than infection. Another study presents a case of fatal breakthrough infection in an older male who experienced myocarditis-like symptoms after his COVID-19 vaccine. Retrospective cohort study of 196,992 adults in Israel did not observe an increased incidence of neither pericarditis nor myocarditis in unvaccinated adult patients recovering from COVID-19 infection. See example case reports. 

REFERENCES

Martina Patone, Winnie Xue Mei, Lahiru Handunnetthi, Sharon Dixon, Francesco Zaccardi, Manu Shankar-Hari, Peter Watkinson, Kamlesh Khunti, Anthony Harnden, Carol AC Coupland, Keith M. Channon, Nicholas L Mills, Aziz Sheikh, Julia Hippisley-Cox Risk of myocarditis following sequential COVID-19 vaccinations by age and sex  medRxiv 2021.12.23.21268276; doi: https://doi.org/10.1101/2021.12.23.21268276

Kim HW, Jenista ER, Wendell DC, Azevedo CF, Campbell MJ, Darty SN, Parker MA, Kim RJ. Patients with acute myocarditis following mRNA COVID-19 vaccination. JAMA cardiology. 2021 Oct 1;6(10):1196-201.

Lazaros G, Anastassopoulou C, Hatziantoniou S, Kalos T, Soulaidopoulos S, Lazarou E, Vlachopoulos C, Vassilopoulos D, Tsakris A, Tsioufis C. A case series of acute pericarditis following COVID-19 vaccination in the context of recent reports from Europe and the United States. Vaccine. 2021 Oct 29;39(45):6585-90.

Hendren NS, Carter S, Grodin JL. Severe COVID-19 vaccine associated myocarditis: Zebra or unicorn?. International journal of cardiology. 2021 Nov 15;343:197-8.

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