The science is clear, too, for unvaccinated people, Walensky said: "You remain at risk of mild or severe illness, of death, or spreading the disease to others. You should still mask and you should get vaccinated right away."
But once someone is fully vaccinated -- two weeks after the final dose -- "you can shed your mask," she said.
Some people may choose to continue wearing masks even if they are fully vaccinated, and that's OK, federal Covid-19 response leaders said Thursday.
"People have to make their own personal choice," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said during the White House Covid-19 briefing.
"There's absolutely nothing wrong with an individual who has a certain level of risk aversion, as we know the risk is extremely low of getting infected whether you're indoors or outdoors. But there are those people who don't want to take that bit of a risk and there's nothing wrong with that and they shouldn't be criticized."