On Tuesday, the FDA approved a second booster shot of either the Pfizer or the Moderna COVID-19 vaccines for people 50 or older and certain immunocompromised individuals.
Those who qualify for the boosters under the new FDA authorization fall into two categories.
Persons 50 years of age or older can get a second booster dose four months after obtaining their first booster shot of the COVID-19 vaccine.
The second group is for people 12 and older who are immunocompromised or have an underlying health condition that makes them more susceptible to severe illness.
The FDA made the quick decision as health experts keep an eye on another variant impacting people in the U.S. and abroad. The new omicron subvariant, known as BA.2, spreads easily and has raised concerns over another surge in worldwide cases.
According to data from the CDC, the subvariant accounts for about 55% of the new cases in the United States.
Experts noted that a second booster might be needed for certain groups, such as older adults or those with underlying medical conditions, in the future.
Other countries, including Chile, Israel, and Sweden, have already authorized a second booster for certain residents. Israel became the first country to approve the fourth dose of COVID-19 vaccines after Prime Minister Naftali Bennett announced that the additional dose would be available to people ages 60 or older and at-risk groups.
The FDA plans to hold a meeting with advisers in early April to assess whether there should be an effort in October or November, in conjunction with the annual influenza vaccine campaign, to encourage some or all adults to get additional boosters. The advisory panel may also debate whether the vaccines should be the same formula as current vaccines or modified for new variants.