I expect that it will be treatments to manage the virus impact, will be the more significant drug intervention, same as with HIV. As far as vaccines go, they have a variety of effectiveness depending on the nature of the pathogen.
1. polio - total immunity
2. tetanus - limited with a booster needed
3. HIV and flu - no immunity or limited to certain strains
4. COVID 19 - who knows, but from what we know of this virus so far, I bet it's not total immunity