[voltaireodactyl]

With regard to the Delta variant, certainly. But it surely has played a role in the subsequent known variants that have appeared as recently as the Olympics.

All of which contribute to our lack of herd immunity, or am I incorrect?

[trdtaylor1]

The current vaccines were/are known to be non-sanitizing. The best vaccines are sanitizing, think measles vaccine. We never were going to reach herd immunity via natural infections and it appears with the current batch we're not going to with vaccines either. Natural infection and a now-canceled nasal vaccine did produce sanitizing effects albeit shortlived.

Towards your original point, only 15% of the world is vaccinated. Say even 5% extra could have been vaxed by now, a difference maybe but nowhere close to the order of magnitude difference required to drop mutation rate below multiple helpful ones per year

[voltaireodactyl]

Thank you for taking the time to explain that — that is largely new information to me and I appreciate the succinct summary with clear starting points to learn more.