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It hasn't been shown yet that achieving natural herd immunity is even an option. Even in countries where they have been very lax on measures there hasn't been e
by efdee 6y ago
It hasn't been shown yet that achieving natural herd immunity is even an option. Even in countries where they have been very lax on measures there hasn't been enough build-up for HI and it also seems that the antibodies go away quite quickly.
- ggreer 6y agoHerd immunity would require that over half of the population get the disease.[1] (Probably closer to 70% based on the virus's R0.) With an IFR of 0.5%, that would mean around 0.25-0.35% of the population has to die before we get herd immunity. No country has come close to that many deaths yet, so we shouldn't expect any of them to have herd immunity. 1. See figure 2 in this paper for a graph of the relationship between R0 and herd immunity thresholds: https://academic.oup.com/cid/article-pdf/52/7/911/847338/cir007.pdf https://academic.oup.com/cid/article-pdf/52/7/911/847338/cir...
- ShroudedNight 6y ago> Herd immunity would require that over half of the population get the disease. Doesn't this also assume that those people remain inoculated to further viral infections after being infected the first time? From my limited understanding, that is not a given for SARS-CoV-2.
- ggreer 6y agoCorrect. This is an optimistic scenario for herd immunity. It assumes low mortality (probably true), no permanent damage to those who survive (unclear, but probably untrue), and immunity lasting a couple years (long enough to remain immune until a vaccine is available).