What is the inoculation of a foreign substance that has reduced virulence called?

The inoculation of a foreign substance that has reduced virulence is specifically referred to as vaccination. Vaccination involves administering a vaccine, which contains killed or weakened forms of pathogens or portions of pathogens (such as proteins) that stimulate the immune system to recognize and combat the disease without causing the disease itself. This process allows the body to develop immunity or a defense mechanism against future infections from the active pathogen.

Understanding this concept is vital because vaccination is a key public health strategy to prevent infectious diseases. While immunization is a broader term that refers to the process of making a person immune, vaccination is the specific method used to achieve that outcome. Inoculation therapy typically implies therapeutic uses of inoculation, and prophylactic treatment refers more generally to strategies aimed at preventing disease rather than specifically utilizing vaccines. Hence, vaccination is the accurate term that reflects the process of using a weakened or inactivated form of a pathogen to induce an immune response.