The definition of “fully vaccinated” could be changed by federal health officials to include COVID-19 booster doses if their data supports it, said White House pandemic advisor Anthony Fauci on Sunday.

While speaking to ABC’s “This Week,” Fauci said that medical officials are still considering the necessity of the booster shot and he personally would not change the definition for what constitutes “fully vaccinated.”

“We’re going to take a look right now at what the durability is of the booster,” Fauci said. “We’re going to follow people who get boosted.”