CDC issued on Thursday allowing vaccinated people to drop their masks indoors, with some exceptions, and outdoors entirely, even in crowds.
"Anyone who is fully vaccinated can participate in indoor and outdoor activities, large or small, without wearing a mask or physical distancing," said CDC Director Rochelle Walensky, MD, MPH. "We have all longed for this moment."
She said that "based on the continuing downward trajectory of cases, the scientific data on the performance of our vaccines, and our understanding of how the virus spreads, that moment has come for those who are fully vaccinated."
The fully vaccinated can start doing the things they stopped doing because of the pandemic, said Walensky.
The only exception to the rule is in certain crowded indoor spaces, such as buses, and planes, and in congregate settings, such as hospitals, homeless shelters and jails, where CDC still recommends people mask up.
And Walensky warned that those who are immunocompromised should speak to their doctors before putting down their masks.
"If you develop symptoms, you should put your mask back on and get tested right away," she said.
The science has shown that those who are fully vaccinated -- 2 weeks since their second dose of either the Pfizer or Moderna vaccines or since having a single dose of the Johnson & Johnson vaccine -- are protected against COVID-19, said Walensky.
She cited a real-world review of Israeli health records -- which found that the Pfizer/BioNTech vaccine was 97% effective against symptomatic infection and 86% effective against asymptomatic infection in more than 5,000 healthcare workers -- and two additional studies published in the Morbidity and Mortality Weekly Report (MMWR) as proof that the vaccinations work.
The first found that vaccines were 90% effective against "any infection" in almost 4,000 healthcare workers; found the vaccines to be 94% effective against hospitalization in older adults.
Additional research on the vaccines' ability to stop -- including the so-called U.K. and South African variants -- provided further reassurance, Walensky said.
In the "rare event" that someone is infected following vaccination, said Walensky, "the resulting infection is more likely to have a lower viral load, be shorter in duration, and likely less risky of transmission to others."
Walensky sounded one note of caution, however. Calling the virus "unpredictable," she said if conditions were to worsen "there is always a chance we may need to make [a] change to these recommendations. But we know that the more people are vaccinated, the less cases we will have, and the less chance of a new spike or additional variants emerging."
She also underscored the specific recommendations for those who aren't fully vaccinated.
"If you are not fully vaccinated you are not fully protected. You need to continue to wear your mask," she said, and encouraged those who are unvaccinated to sign up for their shot.
Earlier CDC guidance, issued April 27, suggested that vaccinated people could safely gather outdoors maskless, except for in "certain crowded settings or venues."
The new recommendations come on the heels of a Senate Health, Education, Labor and Pensions Committee hearing on Tuesday, where a handful of Republican members tore into Walensky for the agency's "conflicting, confusing" and "senseless" guidance, and urged more "real-time" recommendations.
During a White House press conference late Thursday afternoon, President Biden sought to clarify the CDC's recommendations.
"The rule is very simple: Get vaccinated or wear a mask until you do," he said.
Biden reminded Americans that even if they've had their first dose of a two-dose vaccine, they must wait the full 2 weeks until after their second shot.
"Please protect yourself until you get to the finish line," he said. "It's not an enforcement thing. We're not gonna go out and arrest people, but the fact of the matter is I still believe the vast majority of the American people care about the safety of their neighbors and care about the safety of their families."