Within the next 2-3 months, a large part of the global population (at least in the urban areas) will acquire herd immunity. Then the governments will face the dilemma of whether to go ahead with the mass-vaccination or not. In countries such as India, the infection and fatality rates have plummeted by more than half during the last few weeks. Apart from Europe (which is facing the second wave) all the other regions are now in a better state.
and for them to be cured this is where immunity will really be molded up.
Pharmaceutical effect? Of course there would be some but not really into the point that they will lose it completely because people will still hope about vaccination
or some cure out of medicine or some sort not just on relying to other blood or what.