Just eyeballing it.. it seems clearly more impactful (over the medium term) to give 20-40yo their first COVID shot to slow transmission of the virus, rather than give 40-65yo their second shot, which only incrementally lowers their risk of death or transmitting the virus.
I mean this is better even for the older cohort in the medium term because their risk of catching the virus will keep getting lower and lower each week, thanks to vaccinations of young people driving it out of the population.
Has anyone already looked into this in detail? I could make a basic model but it's fiddly and not my area.
When the 1st dose lowers transmission by 75% and the 2nd only gives you another 10%, it's just very hard to see how the 1st shot won't win out over time, as lower spread accumulates.
At this point would you rather permanently lower the COVID fatality rate by 1%, or permanently lower its rate of spread by 1%?
The latter could something like 5x as valuable because it leads to 1% fewer deaths the 1st transmission cycle, ~2% the 2nd cycle, ~3% the third, etc.
Exactly how much more valuable it is depends on the future trajectory of spread, but we're probably in the process of gradually getting rid of COVID over the next 10-20 weeks so should be something on the order of 5x better.