Dr. Anthony Fauci, one of America's leading public health experts, said recently that even after a coronavirus vaccine is developed, Americans will likely need to continue wearing masks and practicing social distancing for quite some time.

In fact, people should expect to wear masks and social distance through the end of 2021 and into 2022, he said.

Fauci, who directs the National Institute of Allergy and Infectious Diseases, made the comments during a Zoom meeting with faculty and students at Thomas Jefferson University in Philadelphia last week.

During the meeting, in which Fauci also predicted any forthcoming vaccine will only be 70% effective, he noted that masks and social distancing will be needed because it will take significant time before herd immunity is achieved.

"You're not going to have a profound degree of herd immunity for a considerable period of time, maybe toward the end of 2021, into 2022," he said. "I feel very strongly that we're going to need to have some degree of public-health measures to continue. Maybe not as stringent as they are right now."

"It's not going to be the way it was with polio and measles, where you get a vaccine, case closed, it's done," he added. "It's going to be public-health measures that linger for months and months."

Fauci also warned Americans against thinking a vaccine will be a "knockout punch" for the virus, noting that vaccines are often less effective against respiratory viruses.

"I tend to be conservative in my projections of what's going to happen," he said. "I think we've got to set reasonable expectations. If I'm surprised pleasantly, so be it."

News of Fauci's comments come as President Trump has been airing criticisms about the health expert.

Trump argued on a campaign call Monday that many Americans are growing tired of strict lockdown measures which have kept the economy from returning to normal levels and have resulted in many Americans losing work.

"People are tired of COVID. I have these huge rallies," Trump said on the call. "People are saying whatever. Just leave us alone. They're tired of it. People are tired of hearing Fauci and all these idiots ... Fauci is a nice guy. He's been here for 500 years."

Trump added later on the call that Fauci has been a "disaster."