The differnces aren't that dramatic in vaccination rates. I think the highest is 70% and lowest is 50%. With this much more contagious variant, even 30% unvaxxed that was not hit hard in the past, with the right weather and other conditions will have outbreak events.What are the most vaccinated states numbers looking like? Should that tell the tale. Being in the south we’ve had a a bad outbreak and we have the lowest vaccinated numbers.
I’d assume vice versa if vaccines work. Compare positives then hospitalizations and then deaths. Surely there is some way to compare.
Within a community, same conditions for everyone. We see huge benefits. That's the apples to apples data or as close as you get.
There are ways to compare the others, but it requires a lot of corrections for all the other differences. This is where people with strong opinions will "know the answer" and make the "corrections" to get the "right" answer.
The unvaccinated are at dramatically greater risk of death, suffering so badly they end up in intensive care, and even simply testing positive. That's the result in every community. The community level requires the least corrections and in nearly all cases those at greater risk are more likely to be vaccinated, so proper correction will show the vaccine more effective than the uncorrected numbers.
So yes, they can be compared, but it's not necessary because we have far more reliable results to evaluate the performance. The only reason to compare different states or countries is desperately looking to find the answer you want if you cannot accept reality.
If you want the truth, you try to find those cases where no correction at all is required. That is the most reliable information you'll ever get. It's rare but when you find it it is the truth. We have that for as close as you get at the local level and they all say the same thing.