The COVID-19 vaccine is very effective at protecting children from severe coronavirus illness and can limit risks of developing additional health issues from the virus.

Published: January 25, 2022

The risk of a COVID-19 vaccine causing heart inflammation in teens and younger children shouldn’t be nearly as scary as the virus itself. Indeed, heart inflammation is a bigger risk among kids who get sick with COVID-19.

“We know that the virus itself causes inflammation of the heart muscle, and inflammation of the heart muscle is more common after infection than after the vaccine,” said Kristina K. Bryant, M.D., physician with Norton Children’s Infectious Diseases, affiliated with the UofL School of Medicine, and hospital epidemiologist at Norton Children’s Hospital. “This is a side effect that is rare.”

Heart inflammation can be caused by the body’s immune response to an infection or another trigger. Symptoms include chest pain, shortness of breath, and feelings of a fast-beating or fluttering heart.

Instances of the mRNA-based COVID-19 vaccines, such as the Pfizer or Moderna shots, leading to heart inflammation in young people have been very rare. While cases have been reported among boys and girls, the Centers for Disease Control and Prevention (CDC) reports that cases of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining outside the heart) are highest among adolescent and young adult males (ages 12 to 29) within several days after receiving an mRNA COVID-19 vaccine, particularly after the second dose. Rare cases of myocarditis have been reported in younger children (ages 5 to 11) after vaccination, although it is very uncommon.

The overall risk remains low, and the CDC estimates 39 to 47 cases of myocarditis among males (ages 12 to 29) and four to five cases of myocarditis among females (ages 12 to 29) after every 1 million second doses of the vaccine.

“In the cases that have been reported thus far, most seem to be mild, and kids recover quickly with medication and rest,” Dr. Bryant said. “If parents have this concern, they should sit down with their pediatrician.”

The rare times that the COVID-19 vaccine led to heart inflammation in teens, medication and rest typically led to a fast recovery and resumption of normal activities.

“The American Academy of Pediatrics has looked very carefully at this data and says the benefits of the vaccine are great, and they outweigh the really rare risk of myocarditis from the vaccine,” Dr. Bryant said.

The CDC recommends COVID-19 vaccines for anyone ages 5 and older. If a child already has received one dose of the Pfizer vaccine, parents should ensure their child receives the second dose, unless their pediatrician tells them otherwise. If a child developed myocarditis after the vaccine, parents should consult their health care provider before scheduling the second dose.

According to the CDC recommendations, everyone ages 12 and older should get a Pfizer COVID-19 booster shot at five months after completing the primary two-shot Pfizer COVID-19 vaccination series. Only the Pfizer vaccine is currently available for ages 12 to 17.