Scientists from the Centers for Disease Control and Prevention and a committee of independent expert advisors convened Wednesday to lay out and discuss everything they know about rare cases of myocarditis—inflammation of the heart muscle—in people who have recently received an mRNA-based COVID-19 vaccine, which is either Moderna’s vaccine or the Pfizer/BioNTech vaccine.
The experts focused on adolescents and young adults, who have had the highest rates of vaccine-linked myocarditis cases of any vaccinated age group. Though, to be clear, all of the rates here—even the relatively high ones—are actually very low.
Still, data on this possible side effect is accumulating at a precarious time for the country’s vaccination efforts. The Food and Drug Administration authorized the Pfizer/BioNTech vaccine for use in adolescents 12 to 15 years old just last month. So far, CDC data suggests those ages 12 to 17 have the highest rates of myocarditis cases by vaccine doses given. And the FDA is poised to review vaccine authorizations for even younger age groups in the coming months.
Many parents, teachers, and caregivers are eager to have their children vaccinated, particularly as youngsters head to summer camps and, ultimately, the start of school in the autumn. Public health experts, meanwhile, are just eager to have as many people vaccinated as possible. Their calls for vaccination have crescendoed recently as they anxiously monitor the spread of the Delta coronavirus variant, which is far more contagious than any variant before it and may cause more severe disease.