While U.S. health officials recommend all adults get their COVID-19 booster shots, they're not currently required to be considered fully vaccinated.
However, that could change in the future as more data on boosters becomes available, Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, told ABC News Nov. 21.
"We'll continue to follow the data, because right now when we're boosting people, what we're doing is following them," Dr. Fauci said. "We're going to see what the durability of that protection is, and as we always do, you just follow and let the data guide your policy and let the data guide your recommendations."
Earlier this month, CDC Director Rochelle Walensky, MD, said the agency was not currently considering changing what constitutes as fully vaccinated.
"The definition of 'fully vaccinated' is one dose of the Johnson & Johnson vaccine and two doses of the either Pfizer vaccine or the Moderna vaccine, and we're not examining changing that definition anytime at this point," Dr. Walensky said during a Nov. 3 White House COVID-19 briefing.
Still, governors Ned Lamont in Connecticut and Michelle Grisham in New Mexico have said they don't consider people fully vaccinated unless they've received their booster dose and are exploring measures to encourage more people to get their booster.
The CDC on Nov. 19 authorized booster shots for all adults who completed their initial COVID-19 vaccination series at least six months ago.
More than 36.6 million U.S. adults had gotten their booster shot as of Nov. 23, or about 19 percent of the nation's fully vaccinated population, according to CDC data.