Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and US President Joe Biden’s chief medical adviser, said Sunday that it's "possible" Americans will still need to wear masks in 2022 to protect against the coronavirus.

In an interview on CNN, Fauci was asked whether he thinks Americans will still need to wear masks next year.

"You know, I think it is possible that that's the case and, again, it really depends on what you mean by normality," he replied.

Fauci said that while he cannot predict when the US might return to operating as it did before the pandemic, he thinks that by the end of this year "we're going to have a significant degree of normality beyond the terrible burden that all of us have been through over the last year."

"As we get into the fall and the winter, by the end of the year, I agree with (President Joe Biden) completely that we will be approaching a degree of normality," he added.

Fauci also weighed on suggestions by researchers in Israel and Canada that just one dose of the Pfizer/BioNTech vaccine was needed to protect against the virus.

"The science points directly towards continuing with what we know about from the clinical trial," which is that two doses provide the most protection against the virus and the emerging variants, he said.

"We know for sure that when you give a prime with the Pfizer followed by a boost 21 days later that you get a 94% to 95% efficacy and the difference between the level of antibodies after one dose versus two doses is about tenfold higher," added Fauci.

"And that is really important because when you have that high a degree comparable to the single dose alone, that's the cushion that you would like to have when you get a variant that isn't as well-protected against by the antibodies induced by the vaccine, but you have enough level to be able to prevent at least severe disease."