By the way, clo, have you been reading that the Pfizer vaccine seems to lose its effectiveness rather fast. Or so Israel is saying.
It may be worth looking at a booster of some sort.
I don't think the US allows foreign vaccines to be approved for use in the US, but the AZ one may have a longer tail than the Pfizer and Moderna ones.
This may also partly explain why the US is suffering so badly with delta.