据说50% 到67% 群体免疫就应该开始。
"Researchers think that the R0 for COVID-19 is between 2 and 3. This means that one person can infect two to three other people. It also means 50% to 67% of the population would need to be resistant before herd immunity kicks in and the infection rates start to go down."
https://www.webmd.com/lung/what-is-herd-immunity#1
拒打疫苗就解雇!多达70%加拿大人说支持