1/21 Several people have asked about whether vaccines will protect against the variants in India. B.1.617 is the major variant of concern, although there are undoubtedly others there. 2/21 Although many are calling it a "double-mutant", this is a misnomer. It carries a number of mutations, but two are concerning. These are found in the receptor-binding domain.

Question for #IDtwitter @soupvector and evolutionary virologists about B.1.1.7 VOC: I see that the 'wild type' SCV-2 had a measured R0 in the UK of 0.95, while B.1.1.7 was 1.45, which is admittedly *greater*. But is that enough to conclude it is much more transmissible? Reminder, Measles R0 is >10. Other points, when uninfected hosts are not limiting, why is wild type being fully replaced by B.1.1.7 unless there is some degree of founder effects?

I haven't seen the calculation for the protective benefit of a #sars_cov_2_vaccine against asymptomatic transmission yet, so here it goes : Suppl. Table 18 in the Moderna NEJM efficacy/safety manuscript: nejm.org/doi/suppl/10.1… Asymptomatic infection at the time of dose #2 administration, appears to be diagnosed by PCR. For the placebo group there were 39 PCR+ infections out of 14598 people; for the vaccine recipients there were 15 out of 14550,