This in unrealistic Sweden tried that and failed. It still imposed some limitations though, yet they have very large death rate. Besides, no one really know how

This in unrealistic Sweden tried that and failed. It still imposed some limitations though, yet they have very large death rate. Besides, no one really know how susceptible he or she is to the disease; there are hundreds of examples of sickly 100+ old people having light cold and young seemingly healthy 35 y old people dying. Even more importantly, the diseases seems to have long term consequences even for the healthier people.