Twitter axed a tweet Sunday by Scott Atlas, a White House COVID-19 task force adviser with no formal training in epidemiology or infectious diseases touted by President Trump as the “anti-Fauci.” Atlas had shared an article from the American Institute for Economic Research arguing that masks are ineffective. “Masks work? NO,” Atlas added in a tweet that was later flagged under the platform’s COVID-19 misinformation policy. Twitter purports to ban “false or misleading content” that may inadvertently cause harm, including posts authored by public health officials or those considered experts.

“Use masks for their intended purpose—when close to others, especially hi (sic) risk,” Atlas wrote in a quote-tweet of his earlier post, which Twitter did not flag for removal. “Otherwise, social distance. No widespread mandates.” Since April, the CDC has promoted public mask usage for everyone, not just those in crowded settings, in order to prevent the spread of the coronavirus that has killed more than 219,000 Americans.