Earlier quoted context omitted.
Would a partial or half immunized population not end up culturing a more resistant strain?
Or could it end up culturing a more mild strain? More like a common cold?
This isn't to say that the progression is certainly in this direction (better evidence of that dates back to 2009 [4]), but hey, there's hope that that's the direction.
[0] https://en.wikipedia.org/wiki/Human_coronavirus_HKU1
[1] https://en.wikipedia.org/wiki/Human_coronavirus_OC43
[2] https://en.wikipedia.org/wiki/Betacoronavirus
[3] https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr...
[4] https://www.scientificamerican.com/article/pandemic-payoff/