Several variables you need to consider:
1. Can a fully vaccinated person still spread COVID. If this is the case, and it certainly is for non-mRNA vaccines, possibly for mRNA as well, then vaccinating 25-45 doesn’t really solve the issue.
2. Vaccine acceptance - if only 25-45% of 25-45y/os vaccinate, you reduce deaths by very little, the strategy only works if a very high percentage of them show up to vaccinate. If you vaccinate the seniors then every vaccine administered is effective at mitigating death in its own right, even if no one else was to vaccinate.
3. How much spread is caused by those 45-60? They’re not the highest death risk, but they’re also not included on your vaccine strategy.
Let me just say that my opinions are 100% boich svaros, and I have no data to back anything up.
1. I don't know. I would think that the viral load any vaccinated person is carrying would be lower, thereby lowering the risk of transmission, but I don't know how much getting vaccinated lowers your chances of being infected, or how much it lowers the chances of you infecting others. If it changes nothing on both counts, we're pretty screwed.
2. If we can only convince 25-45% of that demo to vaccinate, we're in trouble regardless of who we vaccinate first. Ultimately, though, my goal isn't reducing deaths right now. It's cutting the Rt. Without that, any win on deaths is short-lived.
3. Again, I don't have scientific numbers. The 25-45 demo sticks out to me because it seems to be the demo most likely to be employed, have children, and have living parents. When I imagine a Venn diagram of people and the number of contacts they're likely to have, I picture that demo smack in the middle. I may be 100% wrong.