So does this data means that seniors are close to some form of herd immunity?
Only if you can keep them from interacting with unvaccinated people who may be carrying the virus, such as at the supermarket.
So... no.
Also, the sign of herd immunity is not the percentage who've had shots, it's seeing the rate of new cases, hospitalizations, and deaths go significantly down, and stay significantly down.
The current trend is that the falling rates from the last spike is slowing down and is still higher now than it was in the Summer, when we all agreed that is was really bad back then. It's that way now.... just not as bad as it was for the past two months.
And, this is a *novel* coronavirus. We don't know if it takes 60% or 70% or 80% saturation of immunized to reach herd immunity.
While percentage of those jabbed rising is hopeful, look to the stats of hospitalizations and deaths to see if it's *working*.