Under capitalism, the purpose of any occupation is profit. Including medicine. Profit is the most important thing, and therefore, under capitalism, the absence of sick people is unprofitable. More sick people equals more profit.
Under socialism, the goal isn't profit. The goal is to improve human living conditions economically and spiritually. Illness hinders this. And since medicine isn't private, the socialist state organizes a system in which, starting from birth, people receive medical services in all possible forms, from vaccinations to sanatoriums for the sick. Socialism doesn't benefit from illness, unlike capitalism.
I always laugh at conservatives' complaints that social medicine will destroy the US economy. But that's only because a capitalist medical system is impossible without massive theft. The same goes for weapons production. Want decent medicine and no wars? Fight for socialism.