Inoculation with cowpox virus to produce immunity to smallpox is called a(n) inoculation variolation demography vaccination pathogen

Inoculation with cowpox virus to produce immunity to smallpox is called vaccination.

Explanation:

A vaccine is an artificial preparation consisting of suitably treated pathogens (or parts of them) administered for the purpose of providing acquired immunity. This practice, also called vaccination or vaccinoprophylaxis, is able to actively exploit the immune memory of the immune system, allowing the body to develop a defense system against a bacterium, a virus or other microorganism even before coming into contact with it.  

Vaccinations are a fundamental preventive measure for health, the introduction of which has made it possible to reduce the incidence of serious and potentially lethal diseases that have been widespread for millennia, the mortality of vaccinated children and in a few decades, in a safe and extremely relevant way various forms of disabilities in the world.