In a milestone announcement, the Centers for Disease Control and Prevention on Thursday said that those who have been fully vaccinated against COVID-19 do not need to wear masks or practice social distancing indoors or outdoors, except under certain circumstances.

Nearly 155 million Americans have received at least one dose of a vaccine. About 119 million Americans have been fully vaccinated.

"If you are fully vaccinated, you can start doing the things that you had stopped doing because of the pandemic," Dr. Rochelle Walensky said at a White House briefing. "We have all longed for this moment when we can get back to some sense of normalcy."

The news drew a great deal of attention on social media.

Walensky warned that those who are fully vaccinated and develop symptoms should still use masks and get tested. There is also still a requirement to wear masks during travel on buses, trains, planes and public transportation.

“Today is a great day for America,” President Biden said on the Rose Garden. “You’ve earned the right to do something that Americans are known for all around the world: greeting others with a smile.”

The CDC data documented the 10 cases of anaphylactic shock among a reported 4,041,396 first doses of the Moderna vaccine The CDC data documented the 10 cases of anaphylactic shock among a reported 4,041,396 first doses of the Moderna vaccine. Photo: AFP / Ronny Hartmann