@JamesConran1 @wsbgnl @BillHanage Harm per infection has declined a lot in large part due to many more infections. That doesn't imply that total harm has decreased much.
Also, not sure about difficult/costs. The only thing you could do more easily before to avoid infection was get lucky (w/lower prevalence).
@JamesConran1 @wsbgnl @BillHanage 每次感染的危害在很大程度上由于更多的感染而下降了很多。这并不意味着总伤害减少了很多。
此外，不确定困难/成本。在避免感染之前，您唯一可以更轻松地做的事情就是走运（患病率较低）。