A vaccine will only be worth it if it might be a yearly thing and not just a one time thing.
Worth it to whom? The manufacturers? They’re going to make billions on it, even if it’s a one-time thing. There’s about 4 billion people out there who will be able to afford the shot and enough charity money floating around to fund probably another 2 billion.
So far, SARS-CoV-2 hasn’t shown a propensity for rapid mutation. It’s been remarkably stable. That’s great news for us.