The WHO just updated its page on how COVID-19 transmits. Those few sentences on aerosols represent one of the most crucial scientific advances of the pandemic. My NYT piece on the century-long history of the error, the year of delay—and what it means now. https://t.co/B9y2Mf6LC7

This history goes back to scientists trying to get germ theory accepted and fighting (incorrect) folk theories of miasma—infection via stinky air—and they made some mistakes themselves along the way. Some froze into dogma. It took until this pandemic to, finally, start fixing it.

It's a huge advance, not a minor change. It explains so much of what went wrong and how to do better. We started with an incorrect theory of how COVID-19 transmits. One key error goes back a century. And it took a pandemic year to get to even this point. https://t.co/B9y2Mf6LC7

It's a long piece—and honestly, maybe I have maybe 10% of just the narrative in there, and maybe 2% of the history—let alone the fascinating science. I'm co-author on this peer-reviewed piece in The Lancet that explains some scientific details/issues. https://t.co/xPnnWfo75E

It is *really* important for the WHO, the CDC and all the public health agencies to publicize this and lead because there are also a lot of misconceptions—some stemming from the same errors. Masks and distance are still important, for example, but need more context to evaluate.