上奥数题了!
X=2针率
1*X*1:1*(1-X)*7=277:(404-277)
X=93.45%
好吧,看看以色列60+以上两针到底有没有这么高比例!
狗了一下,这里有:
”Nationally, some 90.2% of Israelis age 90-plus are vaccinated with at least two shots, and for the 80-89 age group the figure is 91.5%. It is even higher, 93.1%, for people in their 70s. But the rates decline among younger age groups: 87.2% for people in their 60s; 84.6 for people in their 50s and 81.2% for people in their 40s.“
https://www.timesofisrael.com/among-older-israelis-serious-covid-rate-six-times-higher-if-unvaccinated/
87.2% for 60-70, 所以60以上的大概是上面几个数的平均。(应该是加权平均但没人口数据只好这样粗算),算90.5%,比上面少3%
如果把上面X改成90.5%,算算上面的7倍会变成啥?
1*X*1:1*(1-90.5%)*Y=277:(404-277)
Y=4.83
好吧,疫苗60+目前还是有将近5倍的保护力。
结论,60以上打疫苗还是有一定好处的。