Moderna

If approved, this would be the second booster shot Moderna has issued for people ages 18 and up.

Moderna says the FDA is looking into reports of a rare side effect — myocarditis, or the inflammation of the heart muscle — in those who've gotten the shot.

Moderna will ask the Food and Drug Administration to authorize its vaccine for kids from age 12 to 17 in early June, the company's CEO says.