Thread by @stevesi

1/ This is quite a significant development. Some will say “finally”. Some might say this is wrapped up in politics. For me, journey to this conclusion is kind of a big deal. A look back…

https://twitter.com/DavidElfstrom/status/1307799544697163777

2/ When the first cases hit, public statements from NIH/CDC were solidly about transmission via p2p contact, consistent with cold and flu. Of course there was the famous Fauci comment on handshakes - that was as late as April. npr.org/2020/04/16/836…

3/ Going back before then, however, there were early papers out of China. But these were viewed as anecdotal PLUS many thought information from China was “suspect” at the very least they were not peer reviewed.

4/ Lots of the early discussion of masks echoed the CV Task Force communication that masks were not necessary and air/droplets were not primary vector. This was a typical thread by CNN’s Sanjay Gupta on March 5.

https://twitter.com/drsanjaygupta/status/1235644385771032576?s=21

5/ On March 10 there was a widely circulated story/paper from China about a bus trip where a number of people were infected in proportion to distance from the primary patient extending the distance the virus travels in air. scmp.com/news/china/sci…

6/ In March, WHO published “modes of transmission” document that clearly downplayed the airborne [term of art] nature of the disease. who.int/news-room/comm…

6a/ This is the current FAQ

7/ A March 17 letter to NEJM said airborne was “possible” but pointed out the relative challenges. nejm.org/doi/full/10.10…

8/ On April 20, another paper/story from China broke about airborne transmission and this one was a seating chart at a restaurant [NB, see how good contact tracing is!] nytimes.com/2020/04/20/hea…

9/ This June paper was a review to date and concluded that there was more to learn and essentially validated that the virus is novel, but still not definitive. ncbi.nlm.nih.gov/pmc/articles/P…

10/ By early July, there was a kerfuffle when the lead for CV19 at WHO first said the virus was NOT airborne then backtracked. This was really an argument between scientists over a term of art “airborne” and caused confusion to those following closely. time.com/5863220/airbor…

11/ This shake up led to a letter in Nature outlining why WHO was wrong and the evidence was mounting. nature.com/articles/d4158… The WHO modes of transmission document was then updated.

12/ There were several studies about how far droplets fly. These were all fun and had great visuals (lasers, high speed cameras). But the open question was whether the virus itself was in the drops or just remnants. Same points could have been made with or w/o virus, many said.

13/ A widely circulated letter from researchers at Fauci’s NIH section was even downplayed by Fauci himself on video. The drops fly but the ones with virus fall very quickly in front of you (he said).

14/ All of this if course was enough to create confusion for even those that wanted to do the right thing. In other words, the science was hardly settled. Some dispute that but the evidence wasn’t there to be definitive. Such is a “novel” virus.

15/ But then last week something really interesting came to light—a taped interview between President Trump and Bob Woodward. On Feb 7, Trump said there were reports it was airborne and everyone knew the coronavirus was airborne: It's 'no big thing'
cnbc.com/2020/09/10/tru…

16/ But you have to go back to March when the science was pretty soft. Except the question is who was telling this to the president and what information was that based on? Clearly China was behaving as though it was airborne.

17/ It seems a whole dissertation on responding to unknown can be done on the timeline to conclude Coronavirus 2019 is “airborne” and implications for that. Should the definitions of airborne change? What happens with masks and the WH now? So many questions. // END

PS/ BREAKING: CDC reverses itself and says guidelines it posted on coronavirus airborne transmission were wrong washingtonpost.com/nation/2020/09… // there is no way this happened without politics. Let the FOIA requests begin.

PPS/ 10/5/20 Airborne transmission of SARS-CoV-2 science.sciencemag.org/content/early/… // letter in SCIENCE summarizing airborne nature of Coronavirus. Worth noting this might also be the case for common colds and flu.

PPS/ CDC revises coronavirus guidance to acknowledge that it spreads through airborne transmission cnbc.com/2020/10/05/cdc…

Concluding/ This article from current Nature details the above timeline and includes numerous references.

Face masks: what the data say nature.com/articles/d4158…