In other words, a so-called "leaky vaccine" or a vaccine that lowers the chances of severe illness, but still allows for transmission of a virus, can create conditions that promote the evolution of more virulent pathogens.
For further reading here is a 2015 NIH-funded study that found "imperfect vaccination can enhance the transmission of highly virulent pathogens.". https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4516275/
The chart entitled "genomic epidemiology of novel coronavirus" shows the increase in mutations after the introduction of these leaky vaccines at the beginning of the year.
and its natural immunity that causes herd immunity
What does blood type O have to do with it? O negative or O positive?
Most of my family including me has O type blood
just like mixing up AIDS and HIV in the 80s. wonder if there's any common factors there.