Moderna

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.

The U.S. has pledged to deliver 1.1 billion doses of COVID vaccines to countries in need. Billions more are needed. NPR interviewed the State Department's global vaccine coordinator to learn more.

Moderna says a study in kids 6 to 11 found two doses of the company's COVID-19 vaccine given 28 days apart produced a strong antibody response.

CDC Director Rochelle Walensky also endorsed a mix-and-match approach to boosters that would be flexible for patients and health care providers.

The Food and Drug Administration also gave an OK to boosters that differ from the vaccine originally used to immunize people against COVID-19. A mix-and-match approach could ease the booster rollout.

The recommendation applies to people 65 years and older, those 18 to 64 who are at high risk of severe COVID and those whose work or institutional exposure puts them at high COVID risk.

Should people who get a COVID booster get a different vaccine from their original shot? The results of a highly anticipated study suggest that in some cases the answer may be yes.

The Food and Drug Administration released briefing documents Tuesday on booster shots for the Moderna and Johnson & Johnson COVID vaccines ahead of a two-day advisory meeting that starts Thursday.

But the researchers stressed that all three vaccines, including the Pfizer and Johnson & Johnson shots, provide strong protection against people getting so sick that they end up in the hospital.

Moderna submitted data from 344 volunteers who got a third shot of the vaccine six months after their first two doses. The additional shot significantly boosted immunity, the company said.

Researchers are seeking volunteers in the greater Tampa Bay region to participate in the study to evaluate safety and immune responses. Enrollment will begin in the coming days.

Haiti has received half a million doses of the Moderna COVID-19 vaccine from the Biden administration.