BIDEN INFECTION RISK QUESTION: It entirely depends when Trump got infected.

If Trump just got it from Hope Hicks in 2 days prior to Wednesday, Trump wouldn’t have been able to transmit to Biden so soon at debate.

Unless Trump got it much earlier—but then gets tricky. https://twitter.com/drericding/status/1311895480809512966

2) WORST CASE SCENARIO: Not saying most likely— but if Trump got infected like Hope Hicks from a COMMON SOURCE—then both of them could have been infectious at the Tuesday night debate. And it’s possible he could have tested negative Tuesday (which he said he did) but infectious.

3) Because in this worse scenario—there is a WINDOW OF TIME in which you can be in your incubation time, but infectious, but not test positive yet (usually day 5 or after, sometimes day 4, rarely day 3)—which would allow the gap in which Trump tests negative Tues but infectious.

4) But this requires Trump not to get it from Hope but from another source earlier over Friday-Sunday. Thus, all the stars to line up in a narrow combination of timing for worse case scenario—yet here we are in this crazy timeline in which Hope is positive + president + FLOTUS.

5) That said, this is unlikely. But even if Trump infectious, it would have been very low risk for Biden given the distance between them. But this is why mask, ventilation is so important on top of distance & testing. One needs TAKE ALL THE PRECAUTIONS just in case other fails.

6) And yes, false negative is possible with the rapid tests. Though I don’t know if it was a rapid PCR or rapid antigen, or conventional PCR. But then again, was Hope Hicks testing Tuesday too? Was she positive or negative? Unclear. But we should assume tests accurate.

7) All thus further begs—who and when/where did Trump get it? We need to hunt for cases for way BEYOND Trump. Who else was in motorcade car with her? Kushner and Miller^2? Who else was on AF1 and Marine 1? Who was Hicks near at #Debates2020  ? All this contact tracing matters.

8) Because as @AymanM points out, everyone in the debate hall had to test negative just to be there. And testing done by Cleveland Clinic. https://twitter.com/aymanm/status/1311903201965289472

9) Nasal pharyngeal PCR test are not perfect - actually not good at all more than 1 before symptom onset. This could also be why Hope Hicks tested negative on day of the debate Tuesday yet got ill Wednesday. Hence it could have escaped detection on #Debates2020 night.

10) Bottomline: the risk to Biden from the debate is low, but non-zero. There is a narrow window of negative test from Trump/Hicks, but pre-symptomatically infectious—& during that narrow window spread it via airborne aerosol transmission over the debate stage distance. But low.

11) and yes aerosol transmission can occur in a room with poor air circulation, which is unclear in debate hall.

12) and the 6 feet rule not enough indoors.