Slack / Private Message Drop — page 609

[Kristian Andersen] 3% - that may well be every ~6 months given (a) exposures likely very low titer, and (b) seroreversion to CoVs. I think it's safe to say that a huge number of people are exposed to CoVs on a daily basis - and not just in China. [2021-03-20 09:34:59] [Andrew Rambaut] ~5% serology seems to be the baseline false positive for just about everything - see Ebola in Sierra Leone etc. [2021-03-20 09:35:30] [Kristian Andersen] ... in Africa :wink:. That 2-3% number actually has pretty good baselines [2021-03-20 09:36:00] [Kristian Andersen] Baseline sampled in e.g., Wuhan - of all places. [2021-03-20 09:36:29] [Andrew Rambaut] OK - baseline cross-reactivity with some sort of CoV [2021-03-20 09:36:52] [Andrew Rambaut] See waste-water in Europe in 2019 [2021-03-20 09:40:06] [Kristian Andersen] The 2-3% serological studies were specifically for SARS-like CoVs, with good baselines - so they might well be accurate. But yeah, getting a positive hit on a CoV serological assay - without controlling very closely for background - you can get anything, anywhere. [2021-03-20 09:42:02] [Kristian Andersen] Andrew - since you have a keen eye. Do you know which 'mystery' sequences and viruses Jesse is talking about? I'm quite confused. I think maybe he means these? https://twitter.com/K_G_Andersen/status/1373310963680571397?s=20 Clearly they must be fragments they have managed to successfully sequence, as they mention in the Nature addendum - so absolutely no mystery. Am I missing something? [2021-03-20 09:43:44] [Andrew Rambaut] I was assuming it was those. Some RdRp PCR products I assume [2021-03-20 09:44:18] [Robert Garry] Good to be discussing these points ahead of a likely burst of reporting with the relaese of the WHO report! I already have several reporters promising to call. [2021-03-20 09:45:52] [Kristian Andersen] ... and then this slide showing that they have managed to get some spike sequences too? Clearly very distant. [shared file(s): EvVevMrXcAA_GmP.jpeg] [2021-03-20 09:46:51] [Kristian Andersen]