Thread by @michaelmina_lab

@MarkZlochin @CircusPubes @DrPathHero1 yes.

A very important piece is the temporal relationship between when viral RNA is highest, when antigen tests are highest sensitivity and when people are most likely to be infectious following exposure. While almost no studies directly observe all three together...
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@MarkZlochin @CircusPubes @DrPathHero1 They all fall directly in line with the exact same time period after exposure or - when symptoms are demonstrated, with the same period surrounding onset of symptoms.

So we really do not need empirical data showing transmission and viral load since the kinetics show it all

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@MarkZlochin @CircusPubes @DrPathHero1 A major problem obtaining the direct empirical data is that if someone is testing, they likely aren't infecting others. So, people who are infecting others, you simply are not getting their swab at the same time as they are infecting. So relationships are skewed.

@MarkZlochin @CircusPubes @DrPathHero1 Here is a paper w empirical evidence. It isn't perfect - it is likely biased heavily towards the null - again, b/c by the time someone has a low VL again, it doesn't mean they didn't have a high one a couple days ago when they may have infected the person
thelancet.com/journals/lanin…

@MarkZlochin @CircusPubes @DrPathHero1 This is another very nice paper that observed 300,000+ contacts of PCR positive cases. Observed a clear relationship between the Ct value in the index case decreasing and the likelihood that the contacts led to infections.

modmedmicro.nsms.ox.ac.uk/wp-content/upl…