# Twitter blocks post by Trump coronavirus adviser claiming masks are ineffective

Twitter
TWTR,
-0.47%
blocked the post citing a violation of its policy against sharing false or harmful information.

Atlas’s tweet also contradicts the official guidance from the U.S. Centers for Disease Control and Prevention, which recommends wearing a mask when outside one’s home. There is widespread agreement among health experts that wearing face masks is the simplest and most effective way to curtail the spread of COVID-19 until a vaccine is developed.

Atlas, a Stanford radiologist with no background in infectious diseases, joined the White House coronavirus task force in August. He has been a vocal supporter of Trump and opposes lockdowns in favor of pursuing a strategy of herd immunity.

Also Sunday, Dr. Michael Osterholm, an infectious-disease expert, told NBC’s “Meet the Press” that Atlas’ herd-immunity theory “is the most amazing combination of pixie dust and pseudoscience I’ve ever seen.” Osterholm said herd immunity requires 50%-70% of the population getting infected — far more than Atlas claims — which would likely cause tens of thousands of preventable deaths.

Others have been similarly dismissive of Atlas. Last month, CDC Director Robert Redfield was overheard on a phone call saying of Atlas: “Everything he says is false.”

On Friday, more than 70,000 new coronavirus cases were confirmed in the U.S., and experts warn of a coming wave of cases as winter arrives. To date, more than 219,000 Americans have died from COVID-19.