Ffs. For someone never out of this thread, you don’t really hold information that’s been disseminated many times within it do you?
There are several dozen strains of Flu. There is a vaccine for each and in May of each year, the WHO get together and look at which strains are hitting China. They then recommend which vaccine to produce for whichever strain they think will hit the West that Autumn/Winter.
This isn’t the Flu, nor does it have the mutation ability of Flu due to its RNA type and this one vaccine should be all that’s needed.
https://www.city-journal.org/coronavirus-vaccine