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The CDC has received reports of more than 300 cases of heart inflammation in young people after COVID-19 vaccination, according to NBC News.

More than 20 million adolescents and young adults have been vaccinated in the U.S., the news outlet reported. Although rare, the 300 cases are higher than expected for the age group.

The CDC’s independent vaccine advisory group, called the Advisory Committee on Immunization Practices, was slated to hold an emergency meeting on Friday to talk about the myocarditis and pericarditis cases. The meeting was rescheduled late Thursday after President Joe Biden signed a bill that declared Juneteenth a federal holiday, which will be observed on Friday this year, according to Reuters.

During its regularly scheduled June 23-25 meeting, the committee will discuss the latest research and safety data, as well as a potential link between the heart inflammation cases, and the Pfizer and Moderna vaccines. However, the group isn’t expected to make any changes to its current COVID-19 vaccination recommendations, NBC News reported.

In late May, the CDC began monitoring rare reports of myocarditis after COVID-19 vaccination. The cases seemed to be more common in males than females and occur more often after a second dose of the Pfizer and Moderna vaccines.

The CDC has asked doctors to look for and report patients who have symptoms of myocarditis or pericarditis after vaccination, NBC News reported. Symptoms include fever, fatigue, chest pain and shortness of breath. Most cases have been mild so far.

“The vast majority have fully resolved with rest and supportive care,” Rochelle Walensky, MD, director of the CDC, said Thursday during a White House COVID-19 Response Team briefing.

“I look forward to hearing this important discussion, which is yet another demonstration of our ongoing efforts to keep safety central to everything we do,” she said.

Sources

NBC News: “Over 300 cases of heart issue after Covid vaccination reported in young people, CDC says.”

Reuters: “U.S. CDC delays meet on heart risk from COVID-19 shots due to Juneteenth holiday.”

C-SPAN: “White House COVID-19 Response Team Briefing, June 17, 2021.”