If the vaccine is specific to the spike protein it will do well against that strain. If you remember, the original two doses from pfizer practically eliminated the original variant. Masks were off. People were mingling freely. Life was starting to return to normal. Then in the summer of 2021 the next major variant Delta hit and the vaccines lost some of their effectivness.
Because it's a moving target I don't think vaccines will completely eliminate covid but hopefully will continue to degenerate into less harmful strains and at best become a nuisance. Vaccines should still help prevent severe disease. Speaking from personal experience I was vaxxed with the two original doses from pfizer in the spring of 2021. Earlier this summer I tested positive (likely omicron). Had one of day of symptoms but improved quickly over the next couple of days. By the end of the week I was almost back to normal.
I meant if it's specific to the strain in the spike protein.