CDC says 'likely association' between COVID shot and rare heart inflammation in young people

The CDC says the heart conditions mostly occurred in young men under the age of 30.

The Centers for Disease Control and Prevention said Wednesday there is a "likely association" between rare heart inflammation conditions in adolescents after they received their COVID-19 vaccine.

So far, there have been more than 1,200 cases of myocarditis or pericarditis, which is the inflammation of the heart muscle and the membrane surrounding the heart, respectively, in people under 30 who received either Pfizer or Moderna's COVID-19 vaccine, according to CNBC News.

"Clinical presentation of myocarditis cases following vaccination has been distinct, occurring most often within one week after dose two, with chest pain as the most common presentation," Dr. Grace Lee, chairwoman of the CDC's  Advisory Committee on Immunization Practices.

She also said CDC officials are gathering more data to understand fully the risks and the possible connections.