So the downside of this approach is that if everyone below 40 gets the disease you are entering a situation where the disease is all over the place, and it will be hard to keep the 40+ people fully safe. For example many older people need to be _in a hospital_ for various reasons, which is exactly where the virus is.
In addition you might be inflicting death and long-term disability on quite a lot of those under-40-year-olds.
And I think at the end of it, under 40s immune might not even be enough for herd immunity. You need something like 80% I think.
So the downside of this approach is that if everyone below 40 gets the disease you are entering a situation where the disease is all over the place, and it will be hard to keep the 40+ people fully safe. For example many older people need to be _in a hospital_ for various reasons, which is exactly where the virus is.
In addition you might be inflicting death and long-term disability on quite a lot of those under-40-year-olds.
And I think at the end of it, under 40s immune might not even be enough for herd immunity. You need something like 80% I think.