Slack / Private Message Drop — page 530

[2021-02-20 08:10:32] [Andrew Rambaut] [thread - ID: 2021-02-20 08:10:32] We are writing a paper about the B.1.1.7 variant including its origins and I would love to put some of this speculation in it and then perhaps lay it out in another paper. You interested in being involved? (any of you). [2021-02-20 08:19:18] [Andrew Rambaut] My current favourite hypothesis is that all of this is about increasing transmissibility in the face of global implementation of NPI which is why we have simultaneous explosive 2nd waves (Doug & Phil) and then the 3rd waves (VOCs). In particular I am wondering if partially-effective measures may have driven evolution for transmissibility in the same way that ineffective vaccines can. Doug & Phil arose in China during the first lock down period (but possibly outside of Wuhan in somewhere like Shanghai) but really took off in Italy. Displaced everything globally except for areas like Africa where there was not much reported incidence and not much response and lineage A persisted. Then as incidence started to rocket, NPI were implemented and the lineage A VOCs were selected for. [2021-02-20 08:20:13] [Andrew Rambaut] This would be an explosively political hypothesis given all the anti-lockdown stuff going on. [2021-02-20 08:25:52] [Kristian Andersen] I agree with the first part - not sure about the VOCs. I think the selection pressure there is more complicated with RSA/BRA selecting more for evasion, than inherent transmission. The fixation of mutations was probably due to intrahost selection, but I agree the near-fixation in the population likely has more to do with transmission (in a population with high levels of immunity - so reinfections). [2021-02-20 08:27:16] [Kristian Andersen] [thread - ID: 2021-02-20 08:27:16] B.1.1.7 just looks different to me - again, mutations fixed intrahost in the first place, then near-fixation in the population because of being inherently more transmissible. I think partial immune escape adds to its success as well. [2021-02-20 08:28:48] [Kristian Andersen] But overall, yes, I agree with the hypothesis and think the distinction of different waves being due to different mitigation efforts is a good one - but as you say, massively politically charged. The fourth wave will likely be driven almost entirely by vaccine escape. [2021-02-20 08:29:45] [Robert Garry] Makes a lot of sense to me. [2021-02-20 08:30:19] [Kristian Andersen] (this ain't the flu, btw). Bob, I'll look at the document today! [2021-02-20 09:18:13] [Andrew Rambaut] [thread - ID: 2021-02-20 08:27:16]