Question: As friends see their teens getting Covid left and right, mostly with no or mild symptoms, I see few motivated to get a booster, many stating that the risk/benefit is not worth it. Can you compare the risks of myocarditis in this population with the risk of Covid being more than ‘just a cold?’ Or are we relying on people’s interest in not spreading the disease to the immunocompromised ‘for the common good.’

Answer: Fascinating observation!  First off, it’s really challenging for us individuals to judge risk.  Based on accumulating evidence, we do know that SARS-Cov-2 infection is associated with a higher risk of myocarditis as compared with vaccination (see Q&A of 12/1/21).  Recent estimates suggest that the risk is 3-4x higher after infection as compared with after vaccination; infection is associated with 11 myocarditis events among every 100,000 people and vaccination is associated with 3 myocarditis events among every 100,000 people (see NEJM article).  When it comes to risks of myocarditis following the 3rd dose, initial data from Israel, where boosters have been offered to 12-15 year-olds since late-November, indicate that the risk of myocarditis among younger adolescents post-3rd dose is lower than the risk post-2nd dose (Table 1).  Finally, recognizing that vaccine protection wanes over time and that our current vaccines are less effective at preventing infection from the omicron variant, CDC’s Advisory Council on Immunization Practices (ACIP) met last week to discuss whether booster shots for those ages 12-15 should be authorized.  Based on the evidence available, including a weighing of risks and benefits, ACIP voted in favor of authorization; the benefits of vaccination, including boosting, outweigh the risks.   

Table 1. Myocarditis in Israel (from ACIP slides)