Why would a booster shot for seniors slow the spread if most spread is not occuring in seniors? If they are trying to prevent severe illness, I understand the potential benefits of the third dose, but how does that help for spread which is occuring in young, unvaccinated people?
At this point, if the vaccine helps to greatly reduce spread and severe illness which so far the data coming out of Israel seems to indicate, then the fact that it is not currently effective against getting slightly sick doesn't really matter, because when you have enough people who are vaccinated, spread will slow, and in the meantime severe illness is prevented in vulnerable populations (or anyone who took the vaccine), so there is no reason to go ballistic and lock down again. Just keep on vaccinating and eventually it will die out.
Am I missing something?