The FDA is issuing a new warning on the Pfizer and Moderna COVID-19 vaccines.
It comes after the CDC found a possible connection between the shots and rare types of heart inflammation called myocarditis or pericarditis in people under 30.
So far, about 400 hundred cases have been confirmed. Most of those cases were mild and cleared up quickly.
Doctors say the symptoms to watch for are chest and heart palpitations and shortness of breath.
The CDC still says the COVID-19 vaccine’s benefits far outweigh the risks.
The Delta variant of the virus is continuing to surge in the U.S., especially in areas where vaccination rates are low.
Doctors warn that for those taking their chances without the vaccine, the virus may cause worse heart problems.