If that was true, vaccines would be useless and lockdowns would be futile. There is no reason to believe this virus us somehow different from every other viruswe have ever seen and magically cannot be immunized against.

There are hundreds, if not thousands of viruses we can't be immunized against. They either mutate too quickly, rendering any antibodies we develop moot, or they kill us too quickly. We don't have a great track record in developing vaccines for viruses either.