evidence: Clinical trials and ongoing vaccine monitoring efforts show that COVID-19 vaccines are effective at reducing a person’s risk of severe disease and death. Like any medical intervention, vaccines also come with risks. While COVID-19 mRNA vaccines are linked to a slight increase in the risk of myocarditis (inflammation of the heart muscle), COVID-19 itself is associated with a greater risk of heart inflammation and other health complications. On balance, the benefits of the COVID-19 mRNA vaccines outweigh their risks.