Heart inflammation investigated as possible rare COVID-19 vaccine side effect in teens and young people

• A new study has raised the possibility of a heart condition being a very rare side effect of the Pfizer shot.
• Seven US teen boys experienced chest pain within a few days of having their second COVID-19 vaccine.
• Eligible teens are still being encouraged to be vaccinated, the CDC said.

A new study, published on Friday, has sparked concerns that a heart condition could be a very rare side effect for teens and young adults receiving the second dose of COVID-19 vaccines.

Health authorities are investigating whether reports of heart inflammation in seven US teen boys across several states can be linked to the administration of a Pfizer shot, the Associated Press reported.

The study, published in the Official Journal of the American Academy of Pediatrics, shows that the seven boys - aged between 14 and 19 - experienced chest pain within a few days of having their second coronavirus vaccine.

Heart imaging tests showed a type of inflammation of the heart muscle called myocarditis.

None of the teenagers were critically ill and all were sent home from the hospital after two to six days, Dr. Preeti Jaggi, who co-authored the report, told AP. It is currently believed that the inflammation was temporary, Jaggi said.

Read more: New guidance says businesses can require employees to get vaccinated and bar unvaccinated employees from returning

This study follows news from Israel that suggested there is a "probable link" between receiving the second dose of the Pfizer vaccine and the appearance of myocarditis, Israel's health ministry said on Tuesday.

Out of more than 5 million people who got the vaccine, 275 people reported heart muscle inflammation, mainly young men, the health ministry said.

The US Centers for Disease Control and Prevention last month recommended investigating the possibility of a link between myocarditis and mRNA vaccines, which include those from Pfizer and Moderna, Insider's Sarah Al-Arshani reported

The rate of reported myocarditis cases after COVID-19 vaccinations, however, was not different from the baseline rate, which means there may not be a link between vaccination and the condition, Al-Arshani wrote.

Eligible teens are still being encouraged to be vaccinated due to a rising number of hospitalizations among young people, the CDC said.

The CDC has allowed the use of the Pfizer vaccine for people 12 years old and up.

In the UK, the nation's medicines regulator has approved Pfizer's COVID-19 vaccine for 12- to 15-year-olds.