Bull, and more bull! Having the virus will confer significant immunity. there have been not mutations that could compromise a vaccine, nor are any likely with any Corona virus. Japanese hornets all of a sudden became renamed murder hornets.
I bet you won’t voluntarily be stung by one like that wilderness guy Coyote P.
I thought you were exaggerating, so I did a search for the term "murder hornets." I waded through seven pages of searches looking for an example of where this term was used in the past, and I didn't find a single one.
I did find references to "giant hornets" from 2015, but no old articles using the term "murder hornets."
So now I'm inclined to agree. This name was recently made up to make them seem more terrifying.