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It's more or less epidemiologically impossible that you will see an attack rate of 100% (as you just assumed). Once attack rate reaches >40~60%, the reproductio
by nateberkopec 6y ago
It's more or less epidemiologically impossible that you will see an attack rate of 100% (as you just assumed). Once attack rate reaches >40~60%, the reproduction number drops below 1 because there just aren't enough uninfected hosts.
- Uhhrrr 6y agoIt will probably be significantly higher than 60%, since COVID-19's R0 without lockdown seems to be pretty high. The CDC has estimated it at 5.7 [0]. Herd immunity threshold = 1 - 1/R0, so the threshold would be 82.4%. [0] https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article?deliveryName=USCDC_333-DM25287 https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article?deliv...
- GhostVII 6y agoThat R0 assumes we are taking essentially no measures to stop the virus though, right? I don't no much about it but it seems like the R0 would drop significantly if we keep doing social distancing, expand testing, make people wear masks, etc.
- Uhhrrr 6y agoIt does, but the point of getting to herd immunity is that we don't want to do any of that other stuff.
- s1artibartfast 6y agoThe 5.7 number comes from wuhan, during lunar new year, and before viral identification.