The New York Times said Tuesday that the FDA would make that move as soon as Thursday, citing people familiar with the agency’s plans .
The action would reportedly expand the number of eligible Americans by tens of millions.
The U.S. Centers for Disease Control and Prevention (CDC) committee will meet the next day to discuss the matter.
The booster shots could be made available nationwide as early as this weekend, should the CDC quickly issue its official recommendation.
This comes a little more than a week after Pfizer asked regulators for the authorization of boosters for everyone 18 years old and older.
The vaccine maker also requested Tuesday that regulators authorize its experimental pill for the disease,
Moderna is also expected to submit its own request for the FDA to expand eligibility for its booster soon.
However, vaccine mixing and matching was previously given a green light by both the FDA and CDC for Pfizer, Moderna and Johnson & Johnson boosters.
While some cities and states already allow all adults to get boosters of the Pfizer vaccine, it is not yet official U.S. policy.
In the last week, California, New Mexico, Arkansas, West Virginia and Colorado expanded the shots to all adults. New York City made a similar move.
Boosters are now recommended for people who initially received their second Pfizer or Moderna shots at least six months ago if they’re 65 or older or are at high risk of COVID-19 because of health problems or their job or living conditions. Boosters are also recommended for people who received the single-dose Johnson & Johnson vaccine at least two months ago.
Nearly 31 million Americans have already received a dose beyond their original vaccination.
While members of the panel have debated in prior meetings whether there is sufficient evidence that boosters are currently needed for all adults, cases in some regions of the U.S. are rising.
Patients in hospital beds are by and large unvaccinated, with surges reported in Michigan and Minnesota.
CDC data shows that near 80% of people ages 12 and up have received at least one dose of vaccine and 195.4 million people are now fully vaccinated.
While all three vaccines used in the U.S. continue to offer strong protection against severe COVID-19 illness and death, the shots’ effectiveness against milder infection can wane over time.
The Associated Press contributed to this report