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Slack / Private Message Drop, p.767 [SLACK_000981] · slack_pm:msg:08034

Date: 2021-05-10 08:36
Type: chat message · slack
recipient: Kristian G. Andersen, Robert F. Garry, Edward C. Holmes
speaker: Andrew Rambaut
Topics: Natural origin / zoonotic spillover

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Basically you have gazillion bat viruses. A small fraction of these are human/civet/raccoon dog transmissible but you have millions of these and any transmissible viruses will jump. These will then jump to humans. You have numbers and time on your side. The alternative is a lab samples, say, 10,000 bats (all from a few locations). That sample hasto contain the human transmissible one (but it will not be selecting for it, unlike the carnivore reservoir), it has to stay viable as a virus and infect one person (out of a handful that may be working with the samples). Also the one human infectious virus (out of 10,000 has to be the one to stay viable and infect the lab worker.

In context

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2021-05-10 08:28 Kristian G. Andersen open

Yeah, I was very surprised to see him on here - and disappointed.
2021-05-10 08:30 Andrew Rambaut open

I was thinking more about the false equivalence stuff - perhaps we need a really good figure. Something not like this:
2021-05-10 08:31 Andrew Rambaut open

shared file(s): 2390701C-054C-4D1C-B9DB-1273AC4475CA_1_105_c.jpeg
2021-05-10 08:31 Robert F. Garry open

Baric - aka Deep Throat- is on because Po1 got too much press and we're not really coronavirologists.
2021-05-10 08:36 Andrew Rambaut

Basically you have gazillion bat viruses. A small fraction of these are human/civet/raccoon dog transmissible but you have millions of these and any transmissible viruses will jump. These will then jump to humans. You have numbers and time on your side. The alternative is a lab samples, say, 10,000 bats (all from a few locations). That sample hasto contain the human transmissible one (but it will not be selecting for it, unlike the carnivore reservoir), it has to stay viable as a virus and infect one person (out of a handful that may be working with the samples). Also the one human infectious virus (out of 10,000 has to be the one to stay viable and infect the lab worker.
2021-05-10 08:37 Andrew Rambaut open

If you have zero evidence that SC2 was in the lab then you are left with this vanishingly small prior probability.
2021-05-10 08:44 Robert F. Garry open

? [shared file(s): image.png]
2021-05-10 08:54 Andrew Rambaut open

t proportion of bat viruses that are carnivore/human transmissible e number of exposures between bats and carnivores (over all locations, and over decades) p(h) probability of human infection per carnivore outbreak p(p) probability of pandemic arising per human infection p_zoonotic = t x e x p(h) x p(p) t is very small but e is very large For the lab scenario N = number of samples collected by the lab p(i) = probability a sample remains infectious p(l) = probability of a lab infection s = number of scientists handling material p_lab = t x N x p(i) x (1 - [1 - p(l)] ^ s) x p(p) In this one, t is very small, all of the p() are < 1 and N is not that big
2021-05-10 09:05 Robert F. Garry open

Brilliant! Math>>>Figure

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