NIH director: Mask guidance is 'mostly about protecting the unvaccinated'

Francis Collins, the director of the National Institutes of Health, said on Sunday that the new mask guidance released last week urging fully vaccinated people to wear face coverings indoors in coronavirus hot spots is “mostly about protecting the unvaccinated.”

“Can you clear this up? Do most vaccinated Americans need to wear mask indoors in order to protect themselves and other vaccinated Americans, or is this primarily about protecting unvaccinated Americans, including children under 12 or people who are refusing to get vaccinated?” host Jake TapperJacob (Jake) Paul TapperYarmuth and Clyburn suggest .5T package may be slimmed Fauci on FDA advisers' booster recommendations: 'I don't think they made a mistake' Mississippi governor: Biden vaccine mandates an 'attack' on 'hard-working Americans' MORE asked Collins on CNN’s “State of the Union.”

“It’s mostly about protecting the unvaccinated. That’s where the real serious risks of illness are,” Collins responded.

"But the new news, and much of this comes from that outbreak in Barnstable County, Mass., is that vaccinated people are capable of getting the virus in their nose and throat, and they do seem to have high enough levels of virus that they might be contagious," he added, referring to an outbreak on Cape Cod. "And hence the reason if you're in a community where this virus is spreading, which is about 75 percent of counties right now, it is prudent to put on a mask, even if you're vaccinated, just in case you might be somebody who's spreading it."

The Centers for Disease Control and Prevention announced last week that people who are fully vaccinated against COVID-19 should now wear masks in “public and indoor setting” in sections of the country with “substantial” or “high” levels of transmission, essentially reversing its May announcement that fully inoculated individuals could nix face coverings.

Agency officials pointed to data showing that fully vaccinated people can spread the highly infectious delta variant when announcing the new guidance. The delta variant has taken hold in the U.S., becoming the dominant strain in the country.

During a separate interview on ABC's "This Week," Anthony FauciAnthony Fauci'Highest priority' is to vaccinate the unvaccinated, Fauci says Sunday shows - Boosters in the spotlight Fauci: Data for Moderna, Johnson & Johnson booster shots 'a few weeks' out MORE, President BidenJoe BidenCapitol fencing starts coming down after 'Justice for J6' rally Senate parliamentarian nixes Democrats' immigration plan Biden pushes back at Democrats on taxes MORE's chief medical adviser, said on Sunday that officials know that "vaccinated, asymptomatic, mildly symptomatic people who are infected can spread the infection."

"The fact is, if you get infected, even if you are without symptoms, you very well may infect another person who may be vulnerable," Fauci added. "So in essence, you are encroaching on their individual rights."

Breakthrough cases, referred to as infections detected in fully vaccinated individuals, still remain rare throughout the U.S.

More than 164.2 million people have been fully inoculated in the U.S., and only 125,682 breakthrough cases have been reported in 38 states, according to data collected by NBC News.

Updated at 9:37 a.m.