@tlub The natural immunity probably doesn't last long because the vast majority of the infected people don't even get sick. The viruses don't really want to kill the host and those that do are doomed because their spread is very limited because of their high mortality rate. The first version of SARS is a good example of that. This new version is much "improved" in a sense that it is much milder and therefore has much wider spread. The thing is, lockdown or not, there is no stopping a virus like that. The people who are vulnerable to this virus will get it sooner or later no mater what. The rest of the population will just live with it in the same way they do with a number of other seasonal respiratory viruses. Luckily for humanity, unlike the 2007 SARS, this one doesn't seem to affect young people. This panic lockdown was an utter stupidity on a global scale. If only ten percent of the lockdown effort and cost was focused on protecting the elderly, the effect would have been much, much more meaningful.