CDC backtracks on warning about airborne coronavirus transmission

The U.S. Centers for Disease Control and Prevention (CDC) posted information on its website on Friday, Sept. 18, 2020 about the dangers of airborne transmission of the coronavirus—then removed it three days later. Harvard T.H. Chan School of Public Health experts have criticized the move.

The CDC update originally cited the “growing evidence” that airborne coronavirus particles can spread beyond six feet, particularly indoors when there’s not good ventilation. Joseph Allen, associate professor of exposure assessment science—who has spoken out about the dangers of aerosol transmission of the virus over the past few months—initially praised the update on Twitter. But after the CDC removed the information, Allen posted that there is “a dangerous game being played that is jeopardizing the lives of an already confused public.”

Meanwhile, Howard Koh, Harvey V. Fineberg Professor of the Practice of Public Health Leadership, said that “inconsistency in this administration’s guidance on COVID-19 has severely compromised the nation’s trust in our public health agencies,” according to a September 21, 2020 Boston Globe article.

On September 22, Allen co-authored a Washington Post op-ed on the topic with Linsey Marr of Virginia Tech. The article described the scientific evidence that has shown that tiny coronavirus particles can stay aloft for minutes to hours and can travel across rooms on natural air currents, well beyond six feet.

“Our whole field has been shouting from the rooftops that airborne transmission was happening and that ventilation and filtration were crucial to limiting the spread of the disease,” the authors wrote. “There can be no more denying that this is important, and no more reason for delaying improving the ventilation in our offices, schools and homes. We need the public to heed this guidance in time for winter as we all head back indoors.”

Read the Boston Globe article: CDC deletes new guidance saying COVID-19 can spread beyond 6 feet

Read the Washington Post op-ed: Yes, airborne transmission is happening. The CDC needs to set the record straight

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Scientists warn about airborne coronavirus infection (Harvard Chan School news)