[2aProtectsTheRest]

The R0 for the Delta variant is estimated to be between 5 and 8 (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/997418/Variants_of_Concern_VOC_Technical_Briefing_17.pdf) though judging by the distinction from earlier variants with R0s estimated to be between 4.5 and 5.3, I would guess that R0 is pushing much closer to 8 than 5. Compare that with the R0 of the April 2020 variant of 2.5 or the original Wuhan virus R0 of 1.3. This thing has come an incredibly long way in a relatively short period of time. Based on this data, Delta is almost certainly going to take over new cases around the world.

That may actually be good news. Looking at the UK data linked above, Delta is about 1/2 as likely to result in people over 50 being admitted to the hospital overnight and 1/4 as likely to result in death. I’m not sure how much of the results are confounded by vaccination (they don’t give a breakdown of who among the admitted and dead are fully vaccinated), but any time we see significant reductions in hospitalizations and deaths, that’s a good thing.

[palmer]

I never put much stock in R0. There are two main reasons. First from the German meat plant, some people spread really well, but most do not. Averaging them doesn't work if the superspreader stays home. But more important than that, there are a million social and cultural quirks that affect R0. Case in point, woman in Detroit gets on the bus coughing on everyone and the bus driver and who knows who else is dead a week later. R0 goes down when the stupidspreader stays home.