Twitter on Sunday removed a tweet from one of President Donald Trump's top Covid-19 advisers, which falsely claimed that masks don't work to prevent the spread of coronavirus.
The tweet no longer appeared on the site Sunday morning, replaced with a note saying "This Tweet is no longer available" and a link to Twitter's rules and policies explaining why the company removes or limits certain posts.
The tweet in question, posted Saturday by Dr. Scott Atlas, read: "Masks work? NO: LA, Miami, Hawaii, Alabama, France, Phlippnes, UK, Spain, Israel. WHO:'widesprd use not supported' + many harms; Heneghan/Oxf CEBM:'despite decades, considerble uncertainty re value'; CDC rvw May:'no sig red'n in inflnz transm'n'; learn why."
In a follow-up tweet posted later Saturday, Atlas wrote: "That means the right policy is @realDonaldTrump guideline: use masks for their intended purpose — when close to others, especially hi risk. Otherwise, social distance. No widespread mandates."
Later Sunday, the coordinator of the Trump administration's testing response, Dr. Brett Giroir, the assistant secretary for health at the Department of Health and Human Services, tweeted: "#Masks work? YES!"
"And even though cases/hospitalizations are increasing, we can control #COVID19 by wearing masks when we can't distance, avoiding crowds especially indoors, good hygiene, and smart testing of contacts and to identify/isolate those asymptomatic but infectious," he added.
Trump has leaned on Atlas in recent months, preferring his advice over that of other advisers, like Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. Atlas, a neuroradiologist who isn't an expert in infectious diseases, gained attention after he made a number of appearances on Fox News. He has pushed more aggressively to reopen sectors of the economy, and he is regularly seen at the White House without wearing a mask.
Last month, an NBC News reporter overheard Dr. Robert Redfield, director of the Centers for Disease Control and Prevention, telling a colleague in a phone call that Atlas is arming Trump with misleading data.
"Everything he says is false," Redfield said during a phone call made in public on a commercial airline.
As the election nears, Twitter has taken a more aggressive approach to limit and remove misinformation, especially relating to the coronavirus and voting. The website has slapped a warning label on several problematic Trump tweets in recent months.
Trump, who tested positive for Covid-19 this month, attended a crowded church service in Nevada on Sunday. He and his aides didn't wear masks at the ceremony, which was held indoors with over 200 people in attendance, many of whom also forwent face coverings.