Appearing on CBS's "Face the Nation," Fauci explained to host John Dickerson that fully vaccinated people can go without masks even if they have an asymptomatic case of COVID-19 because the level of virus is much lower in their nasopharynx, the top part of their throat that lies behind the nose, than it is in someone who is unvaccinated.
"So even though there are breakthrough infections with vaccinated people, almost always the people are asymptomatic and the level of virus is so low it makes it extremely unlikely — not impossible but very, very low likelihood — that they're going to transmit it," Fauci said.