Bletchleyite
Veteran Member
Neither of those mean that there is a viable vaccine to be discovered, unfortunately. Previous attempts have resulted in either low efficacy, or the vaccinated individual suffering extreme and dangerous immune response such as cytokine storms when subsequently infected by the target virus.
It is indeed possible that one is not viable. However, if one is viable, it will likely be found, rather than e.g. cost being a barrier.
It's also possible that a treatment will be found. If we could viably stop it killing people or causing major organ damage it is then only an irritant like the flu.