like Warrigal says all viruses mutate all the time. Result is new variants and strains, all the time. Not just COVID, all viruses. That's part of the reason we get flu shots every year, to address the new variants of the flu. In the end I am sure COVID will be the same, and boosters or new vaccines will be necessary periodically. I think it may just end up as a part of the flu shot cocktail we get every fall. The vaccines are still effective against these variants, but a bit less effective, and that will continue to be true until we get boosters or new vaccines. No vaccine is ever 100% effective, some risk still exists, just much lower. Its how vaccines always work.
A big difference between COVID and the flu and other viruses is we are paying close attention and the new variants make for headline news. New variants of the common cold are more common but we pay them no attention.