Elizabeth Brown, a mother of two who lives outside Denver, Colorado, had a tough decision to make when childhood COVID-19 vaccines became available. Her five-year-old was born with a congenital heart defect that required a risky surgery when he was two years old to avoid a lifelong risk of heart inflammation from infection. But Brown also knew that after getting some COVID-19 vaccines, adolescent boys are at risk of developing myocarditis, a different kind of inflammation of the heart.
”To read about children with no cardiac history having myocarditis as a pediatric vaccine complication was scary,” Brown says. “There were a lot of inflammatory headlines from the media that preyed on a parent’s fear in terms of the vaccination and very little information readily available regarding the damage COVID can do.”
Brown spoke with her son’s cardiologist and mulled it over for weeks. As more information came out, she says, “I became more confident in vaccination.” Her son received his first vaccine dose two weeks ago.
Many pediatricians and pediatric cardiologists lament that myocarditis—a rare side effect from the mRNA COVID-19 vaccines in adolescents—has been hyped, receiving arguably more attention than the life-saving benefits of the vaccine. Likewise, they say, some physicians who treat adults have minimized the threat that COVID-19 poses to children. Meanwhile, two members of the advisory board that recommended the Food and Drug Administration authorize the vaccine for children between ages 5 and 11 have questioned whether all younger children should be vaccinated before there is more information on the risk of myocarditis.
The mixed messages have left parents feeling confused and uncertain. Although more than one million children ages five through 11 in the U.S. have now been vaccinated, a substantial proportion of parents remain uneasy about it, according to a recent nationwide survey. Shortly before the FDA authorized the Pfizer vaccine for younger children, one in three parents planned to “wait and see” before vaccinating their kids, according to a Kaiser Family Foundation poll. Another 27 percent planned to vaccinate their kids immediately, while 30 percent said they would not vaccinate their kids at all.
Yet review of more than two dozen articles in peer-reviewed medical journals, government documents, and interviews with 10 pediatric cardiologists and pediatricians offer a reassuring picture of the safety of pediatric COVID-19 vaccination. Myocarditis after the vaccine is rarer and usually milder than the cardiac complications from COVID-19, including those from multisystem inflammatory syndrome (MIS-C), says Matthew Elias, a pediatric cardiologist at Children’s Hospital of Philadelphia. MIS-C is a serious condition that can occur two to six weeks after an acute SARS-CoV-2 infection in about one out of 3,200 infected children, even if the infection was mild or asymptomatic. MIS-C can involve inflammation of many organs, including the heart, lungs, kidneys, brain, skin, eyes, and digestive organs. The Centers for Disease Control and Prevention reports that more than 5,500 U.S. children have had MIS-C since the pandemic began, though experts believe that’s an underestimate.
“The pediatric hospital experience shows that the risk of patients at any age having cardiac involvement from COVID is uniformly worse than vaccination myocarditis risk,” says Frank Han, a pediatric cardiologist at OSF Healthcare in central Illinois. Like Elias, Han says most vaccine-associated myocarditis cases are mild, without “significant disturbance to the heart function or inability to maintain blood pressure.”
Different types of myocarditis
Broadly speaking, myocarditis refers to inflammation of the heart and can involve a wide range of symptoms and severity, from very mild pain to heart failure, explains Elias. But different types of myocarditis exist, including three types related to COVID-19: myocarditis from the SARS-CoV-2 infection itself, from COVID-19-triggered MIS-C, and from the vaccine.
Myocarditis during a COVID-19 infection is similar to the classic myocarditis that pediatric cardiologists use to describe what they see with some non-COVID viral infections. But this classic type is more frequent in adults with COVID-19 and rarely occurs in children sick with COVID-19.
What’s far more common in children is either myocarditis from MIS-C, or cardiac symptoms associated with MIS-C that resemble myocarditis. Part of the confusion over pediatric rates of myocarditis related to COVID-19 stem from trying to characterize the cardiac symptoms of MIS-C—whether to call them myocarditis or not—since MIS-C is such a new phenomenom.
What most pediatric cardiologists agree on is that cardiac complications seen with MIS-C are more serious than the myocarditis seen from the vaccine.
Though nearly all children who suffered cardiac problems connected to MIS-C have since recovered, the long-term effects remain unclear. Some children with MIS-C get coronary artery aneurysms, in which a coronary artery widens well beyond what’s considered normal, says Jacqueline Szmuszkovicz, a pediatric cardiologist who specializes in MIS-C at the Heart Institute at Children’s Hospital Los Angeles. Though rare, these aneurysms can sometimes be fatal. They also require long-term follow-up, possibly until adulthood, since they may affect a child’s future risk of coronary artery disease, Han says. Importantly, these aneurysms have been seen with MIS-C but not with the vaccine.