SARS-CoV-2 infection raises the risk of myocarditis 11-fold but inoculation with any COVID-19 vaccine halves this, according to the largest risk analysis to date.

And the probability of vaccine-induced myocarditis is also much lower than the risk associated with infection, the data show. 

The exception is for men aged under 40, who had a greater risk of myocarditis in the month following their first dose or second dose of Moderna vaccine than after coronavirus infection.

Adding to the complexity, in women under 40, the number of excess myocarditis events were similar after two doses of Moderna vaccine to the number after infection.