Scott Hensley

Watch an expert panel discuss the latest developments and challenges in the COVID-19 pandemic livestreamed at noon ET on Friday.

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.

The companies studied a 10 microgram vaccine dose in children 5 to 11, a third of the dose used for adults, to minimize side effects and because it still prompts a strong immune 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.

A panel of experts voted to recommend that the Food and Drug Administration authorize a booster dose of the Johnson & Johnson COVID vaccine at least two months after the first shot.

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.

Johnson & Johnson has asked the Food and Drug Administration to authorize a booster for people 18 and older six months after initial immunization, with an option to vaccinate after two months.

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.

A third shot of the vaccine can be given at least six months after the two-dose regimen, according to the authorization. A booster rollout could begin this week.

Advisers to the Food and Drug Administration supported boosters of the Pfizer-BioNTech COVID-19 vaccine for a smaller group of people after they voted against recommending it for anyone 16 and older.

Pfizer says data supports its request for Food and Drug Administration approval of a third dose of the COVID-19 vaccine about six months after the second dose in people 16 years and older.

The approval replaces the emergency use authorizations granted last December and could make it easier for employers, the military and universities to mandate vaccination.

This is the first new drug approved for Alzheimer's disease since 2003. It's the first to show significant progress against the sticky brain plaques that are the hallmark of Alzheimer's disease.

Updated study results say the vaccine is 76% effective against symptomatic COVID-19 and 100% effective against severe disease. Independent monitors had been concerned about a previous report.

The Food and Drug Administration gave Johnson & Johnson's vaccine the green light for emergency use Saturday, a day after a panel of advisers to the agency endorsed it in a unanimous vote.

The Food and Drug Administration typically follows the advice of its expert advisers. A quick agency decision on the Johnson & Johnson vaccine is expected given the state of the pandemic.

The Food and Drug Administration released an analysis of Johnson & Johnson's COVID-19 vaccine Wednesday morning that appears to support its authorization for emergency use.

The vaccine did better at preventing disease in the U.S. – 72% — and less well in South Africa – 57% efficacy. The efficacy seen in Latin America was 66%.

Novavax says its COVID-19 vaccine is 89% effective at preventing illness, according to an interim analysis of a U.K. study. But the vaccine wasn't as effective against some viral variants.