By CBSBoston.com Staff

WASHINGTON (CBS) – The Pfizer COVID booster shot could be available to all adults by the end of this week.

A person familiar with the plans tells CBS News the Food and Drug Administration could approve Pfizer’s request to make its booster shot available to everyone 18 and over as early as Thursday.

The Centers for Disease Control and Prevention’s advisory committee is expected to take up the topic Friday afternoon. They will make the formal recommendation after the FDA’s expected authorization, and then CDC Dr. Rochelle Walensky will likely sign off on the plan.

If that happens, anyone 18 and older who received a second dose of a COVID vaccine more than six months ago could go out and get a booster shot as early as this weekend.

“Applying for boosters for everybody gives us a chance to get the vaccines back to the effectiveness we saw early on. We now know the vaccines start to lose their effectiveness over time, especially after the six month period,” Dr. Paul Sax, the clinical director of the infectious disease clinic at Brigham and Women’s Hospital in Boston, told WBZ-TV Wednesday.

Some states and cities already allow all people ages 18 and up to get boosters of Pfizer’s vaccine. Federal approval would allow the boosters everywhere in the U.S.

Only Pfizer will be available initially. Anyone who got Johnson & Johnson’s single dose vaccine and vulnerable groups that received Moderna’s two-shot vaccine are already eligible for booster shots.

Cambridge-based Moderna also reportedly plans to submit a request to expand access to its booster soon.

Dr. Mark Siedner, a clinical epidemiologist at Massachusetts General Hospital, said this all comes at a critical time entering winter.

“Now that we’re seeing cases go up both here in Massachusetts, but actually across the country, hospitalizations rates are going back up. If the epidemic surges again we need as many people protected as possible and the boosters will help with that,” he told WBZ.

“Only time will tell how long immunity will last with the boosters, though some expect the protection to be more durable than with the initial vaccinations,” said WBZ-TV’s Mallika Marshall.

CBSBoston.com Staff