Mullardman
Moderately extreme...
Covid-19 is a flu virus.
Whilst I'm in broad agreement with most of your post.. Covid is definitely NOT a 'flu' virus. It is this fact which creates much of the problem. Covid-19 is a new form of Coronavirus. Coronaviruses are responsible for assorted forms of the Common Cold... and research for many decades did not come up with a vaccine against the 'Common Cold'
As far as I can tell.. Covid-19 itself does not kill. It is the extreme antibody reaction of some people's bodies to the virus which causes a massive pneumonia..which in turn can be fatal, through lung damage. and.. in effect. drowning. I've not yet read anything which points to a way of identifying who is more at risk, other than the general efect of age. What I suspect is needed.. is a way to tell which PREVIOUS infections have an influence on any individual's reaction to Covid.