100 years from now, given natural infection/vaccination prevents sickness but doesn't stop transmission, everyone will be exposed either through vaccine/natural infection/both well before they enter the higher risk demographics.
One thing I'm not sure if the article touched on (couldn't read it behind the paywall) is the natural tendency for viruses to become less harmful as they mutate/evolve.
It's weird to think of a virus trying to do something, but really they just 'want' to reproduce. Which means infecting something.
The more harmful a virus is the less people it will infect. Taken to the extremes, look at a virus that kills the host within a minute of infecting them. That virus ain't spreading very far. Conversely, if it does absolutely nothing and causes no symptoms, well, people will happily carry its viral ass with them wherever they go. And, the virus will reproduce and be transmitted to others.
Viruses obviously don't make decisions on how harmful they are. (Only governments do that, I kid, I kid
) But, given the shear number of Sars-Cov-2 in the world, there will be mutations and those that cause less harm to the host will invariably spread more. Given enough time, no idea how long probably decades, those strains that do less harm will circulate more giving the body exposure without serious adverse effects. The strains that do more harm will be recognized, isolated, and the virus will die. So, even ignoring vaccines, on a long enough timeframe (much longer than we would want to rely on), Sars-Cov-2 will very likely weaken almost to a point of unrecognition.
