Just days after publishing significant new guidance on airborne transmission of the coronavirus, the Centers for Disease Control and Prevention on Monday withdrew the advice, saying only that it had been "posted in error” on the agency’s website.

The rapid reversal prompted consternation among scientists and again called into question the credibility of the world’s premiere health agency, even as President Donald Trump and his senior health officials have sought to undermine CDC scientists. The president faces an election whose outcome may turn on public perception of his handling of the coronavirus pandemic.

The turnabout arrived as the number of virus-related deaths in the United States approached the 200,000 mark. Tens of thousands of new infections are reported every day, and experts fear a resurgence as cooler weather approaches and people spend more time indoors.