First identified in India in December 2020, Delta swept rapidly through that country and Great Britain before reaching the U.S. India did not have any vaccine at that time. So, with Delta we have an example of a mutant variant that did not come because of any vaccination program. As I said, we got the Delta Variant without the help of the vaccine.
Not necessarily true.
I live in King County (Seattle).
Every day, and through out 2020, dozens of Asian Indian software engineers arrived at SeaTac airport or departed back to India.
Thousands of engineers and their families returned to India after being vaccinated in the USA.
It is also noteworthy that the Delta virus emerged in the same time period that Chinese and Indian soldiers were killing each other over a disputed border region.
It is entirely possible that the Delta variant emerged from the same lab that created COVID-zero, and that it was deliberately spread around India by the Chinese.
“So, with Delta we have an example of a mutant variant that did not come because of any vaccination program.”
Viruses tend to mutate, particularly coronaviruses, but a mutated variant would remain rare, or vanish, if it didn’t have the ability to replicate more effectively than the original form.
The vaccines create an artificial selection advantage for any variant that can elude the narrow immunity that they provide. That, I imagine, is how a rare variant in India became the dominant strain worldwide.