The FDA advisory panel on Friday voted 18-0 in favor of booster shots for anyone 65 and older or anyone at high risk of severe disease from COVID-19.

If the FDA agrees with the plan, which is likely, it’s possible that booster shots would roll out as early as next week to these populations. The CDC would weigh in first though with more specific recommendations on who exactly should take the third shots.

The 18-0 vote comes after the members voted "no" on the question of whether the current data supports a booster shot of the Pfizer vaccine for anyone 16 and older.

The independent FDA advisory committee voted "no" on Friday on the question of whether the current data supports a booster shot of the Pfizer vaccine for anyone 16 and older. 

This was largely due to members’ discomfort with the vast age range this question includes. As members of the FDA's Vaccines and Related Biological Products Advisory Committee outlined in Friday's meeting, there are still large gaps in safety and efficacy data for the younger age groups. But the members said they haven't ruled out third shots for older populations.

The panel will now vote on boosters for everyone over 65 and people who are at high risk of the virus.

Moderna's two-shot vaccine seems to offer the strongest protection against hospitalization, though all three vaccines dramatically reduced the risk, according to a new analysis published in the CDC's weekly report MMWR.

The study used a model to estimate effectiveness against hospitalization among 3,689 adults hospitalized from March to August. According to the estimate, vaccine efficacy against hospitalization was: 93% for Moderna; 88% for Pfizer; 71% for Johnson & Johnson.

This study did not specifically analyze delta, did not include people under 18 nor did it include immunocompromised people. This study did look at antibody levels but didn't track a change in antibody levels over time. 

-ABC News' Sony Salzman, Adela Wu

White House COVID-19 response coordinator Jeff Zients said when boosters start rolling out he's confident there won't be a supply problem as there was when vaccinations began.

“We have plenty of supply of all three vaccines for boosters, obviously pending the FDA and the CDC recommendations," Zients said at Friday's White House COVID-19 Response Team briefing. "We have supply in inventory and we also have supply on order. So supply is in good shape for all Americans to get boosters."

At the briefing CDC Director Dr. Rochelle Walensky announced a $1.2 billion dollar investment in building more resilient health care systems to battle COVID-19 and future illnesses over the next three years. 

-ABC News' Matthew Vann