Vaccinated individuals must NOT donate "convalescent blood" as their blood will kill natural immunity in those who have not been vaccinated but have had (and recovered) from Covid19. Red Cross accepting blood donations from vaccinated, but not for convalescent blood. Sooo.... the intention of the donation makes NO DIFFERENCE if you have natural immunity - blood from vaccinated individuals will still kill natural immune cells. "BUT THE VACCINE WIPES OUT THOSE (NATURAL) ANTIBODIES..." (which offer much more robust levels of protection than any vaccine). Vaccines do NOT prevent transmission of Covid19, and those who have received vaccines may still get it. The shots ONLY reduce severity of symptoms when someone gets Covid19 (WHO, CDC). This means that no immunity is possible from Covid19 vaccinations. And NO HERD IMMUNITY. Those who have had Covid19 and recovered have immunity, and some studies project that this immunity may last 11 years or longer. Perhaps a lifetime. Everyone will eventually get Covid19, whether vaccinated or not. This is when it will naturally subside.