And that is one of main issues with the COVID vaccines that those who argue against their effectiveness forget. They were first developed to handle the original variant, but by the time they were being administered, the Delta variant was dominant and the vaccines haven’t been as effective against it. Now there is a new variant out of South Africa and they don’t know if the vaccines will be effective against it.
The problem becomes, then, that the longer the virus is in populations with high numbers of unvaccinated, the more variants we will have, with the possibility of ones that are worse and better at evading then vaccines.