Fauci Says Herd Immunity Possible ‘Reasonably Quickly’ If Enough Americans Take Vaccine

Dr. Anthony Fauci, the nation's top infectious diseases expert, said Sunday the U.S. could reach herd immunity against the coronavirus "reasonably quickly" next year if enough Americans get vaccinated.

Appearing on "Face the Nation," Fauci said "help is on the way" in the form of the vaccine, but Americans need to exercise caution as the holidays approach and take steps to mitigate the spread of the virus through the winter, saying the country is in a "very, very difficult situation" as cases continue to rise. Vaccines will be available "relatively soon" if Americans can "hang in there," Fauci said. 

Vaccines produced by Pfizer and Moderna have been shown to be highly effective, but Fauci said herd immunity — the threshold at which enough people have been vaccinated or infected by the virus to curtail its spread — can't be achieved if only 40% or 50% of the population receives the vaccine, Fauci said. Polling has shown Americans are still skeptical of a vaccine, and many say they will either delay vaccination or won't get it at all. 

"What we do need is we need to get as many people as possible vaccinated, and that's why we want to be very transparent for people to understand" the process that goes into the vaccine's creation and approval, Fauci said. 

"The FDA will examine it very carefully now together with advisory committees that are completely independent, and declare with the EUA and ultimately a license that the vaccines are safe and effective," he said, referring to the process for obtaining an emergency use authorization. "When the American public hears that, you should be assured that that is the case. And if you get an overwhelming majority of the people vaccinated with a highly efficacious vaccine, we can reasonably quickly get to the herd immunity that would be a blanket of protection for the country."

Fauci, the head of the National Institute for Allergy and Infectious Diseases, also urged caution going into the holidays, as 50 million Americans are expected to travel for Thanksgiving. He said the crowds at airports during travel can present unsafe situations, even as airlines try to mitigate those risks. There's also a significant risk in gathering with others outside one's household, particularly if there are older relatives or people with underlying conditions present, he said.

The increase in cases attributable to Thanksgiving gatherings won't be evident "until weeks later," Fauci said. 

"Those are the things we've got to realize are going to get us into even more trouble than we're into right now," Fauci said.

The rising case numbers shouldn't be seen as a hopeless situation, Fauci said, urging Americans to wash their hands, distance from others and wear masks to mitigate the risk of spread. 

"There's a very sober message on the one hand, but there's a hopeful message if we do certain things. It's within our power to do them."

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