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What everyone seems to be assuming is that this new strain will cause a constant increase in the reproduction number R of ~50% in every situation. I haven't rea
by cactus2093 6y ago
What everyone seems to be assuming is that this new strain will cause a constant increase in the reproduction number R of ~50% in every situation. I haven't really seen any discussion of if and why that is actually a good extrapolation to make.
So for example in a specific situation, with a specific type of intermingling of a population in which the R value was, say, 1.2, we think the new strain caused that to increase to an R value of 1.8. How does it necessarily follow that taking intervention measures that bring the R value of the base strains down to, say, 0.8 would bring the R value of the new strain to exactly 1.2?
There are just so many factors involved, it doesn't seem like this could possibly be knowable right now. So there may be some hope that things like getting everyone N95 masks and requiring their use, and closing down indoor activities, which are good measures to control the current strains anyway, could also bring down the reproduction number of the new strain below 1 as well.
However, this is all a purely academic exercise anyway. Even in places that are being "aggressive" in countering the virus like San Francisco, we have done exactly nothing to react to new information in the past 1.5 months. Our "lockdown", which is entirely optional and has no teeth, is clearly not working, but we have neither removed it or strengthened it. The health department has exactly zero plans regarding the vaccine. It feels like we've just given up altogether, and we're praying that the private market saves us by somehow distributing the vaccines effectively. And on top of all that, we've handicapped the private market by making it illegal to distribute the vaccine to the vast majority of the population, even the elderly and vulnerable groups!
- potshot 6y ago> The health department has exactly zero plans regarding the vaccine I'm in San Francisco and a family member runs a specialty clinic here. They worked directly with the health department last week to get their staff vaccinated as part of Phase 1a described here: https://sf.gov/covid-19-vaccine-san-francisco https://sf.gov/covid-19-vaccine-san-francisco I'm not saying the performance so far is outstanding or good, but it's simply not true that the health department "has exactly zero plans regarding the vaccine".
- cactus2093 6y agoI mean members of the board of supervisors can't even figure out if the health department has an actual plan or what it is https://twitter.com/MattHaneySF/status/1349189438241325057 https://twitter.com/MattHaneySF/status/1349189438241325057 I guess "exactly zero" is poor wording, but they seem to only have a very loosely defined plan that hasn't bothered going beyond phase 1A tier 1 even though vaccines started being distributed a month ago and 2/3 of them statewide are just sitting around.
- bonzini 6y agoThere are cases where restrictions have an additive rather than multiplicative effect on the reproduction number, but after better modeling they often end up as ultimately multiplicative. For example, let's say you observe "closing schools" to bring Rt from 3 to 2.7, "closing offices" to bring Rt from 3 to 2.3, and "closing both" to bring RT from 3 to 2. What's really happening is not that the two restrictions have a -0.7 and -0.3 effect. Instead, the two apply to almost disjunct subsets of people. Therefore it is more accurate to say that the "closing both" restriction is a *0.66 reduction of the reproduction number, while "closing schools" and "closing offices" only apply that 0.66 factor to a subset of the population. What is really additive is the amount of people affected by the restriction.