U.S. health officials say Americans who are fully vaccinated against COVID-19 do not need to wear face coverings or social distance in most places.

    The change means that the United States can begin to re-open society and the nation after the year-long coronavirus health emergency.

    Dr. Rochelle Walensky is the director of the Centers for Disease Control and Prevention, known as the CDC. She said Thursday, "Anyone who is fully vaccinated can participate in indoor and outdoor activities – large or small — without wearing a mask or physically distancing."

    Walensky added, "If you are fully vaccinated, you can start doing the things that you had stopped doing because of the pandemic."

    She said the decision is based on the decreasing number of COVID-19 cases in America and the agency's understanding of how the virus spreads. She noted that studies from the U.S. and Israel have shown that the approved vaccines are strongly protective in real situations. The vaccines, she added, continue to work although new versions, or variants, of the virus are spreading.

    The new CDC guidance, however, still calls for wearing masks in settings like buses, airplanes and hospitals. And Walensky also advises people with weak immune systems, such as those undergoing cancer treatment, to talk with their doctors before giving up their masks.

    The CDC reported this week that about 154 million people in the United States have received at least one shot of vaccine. The agency noted that more than 117 million have been fully vaccinated.

    This week, the U.S. Food and Drug Administration (FDA) also permitted the use of the Pfizer/BioNTech vaccine for children as young as 12.

    The new guidance comes as the U.S. is starting an aggressive campaign to vaccinate those who have not yet received the shots.

    On Tuesday, U.S. President Joe Biden talked about a partnership with companies to provide free transportation for people to and from vaccination centers. He also told the nation's governors, "We have to make it easier and more convenient for all Americans to get vaccinated."

    In Ohio, Governor Mike DeWine announced a weekly lottery worth $1 million for those who have received the shots. Younger people would be in a lottery to win a chance to attend college at no cost.

    The new guidance had immediate effect at the White House.

    President Biden appeared in public for the first time without a mask since the start of the pandemic. He cheered the CDC's guidance and told Americans, "So for those who haven't gotten their vaccination yet, especially if you're younger, or think you don't need it, this is another great reason to go get vaccinated now."

    And White House employees were told that masks are no longer required for those who are fully vaccinated.

    I'm Bryan Lynn.