I get a flu vaccine every year, because just like Covid, the flu mutates. Last year's flu shot won't protect you from this year's flu.
Each year, there are several variants of the flu virus going around. The flu shot protects you from the most prevalent variant.
And that is how it will be going forward with Covid. Covid will always be with us, and each year we will get a shot which protects us from the most prevalent variant.
People in the future will laugh at the ignorance of the present day Covid anti-vaxxers.
"Did they refuse the polio vaccine, too?"