What does the term "natural immunity" refer to?

The term "natural immunity" specifically refers to the immunity that arises as a result of natural exposure to pathogens, such as viruses or bacteria. This type of immunity develops when the immune system is exposed to a disease-causing organism and learns to recognize and fight it off in the future. For example, if a person contracts an illness, their body produces antibodies that can recognize and combat that specific disease if encountered again, which forms a memory in the immune system.

In contrast, immunity obtained through medical treatment typically involves vaccinations or other therapeutic interventions, differentiating it from the naturally acquired immunity provided by the body's own response to pathogens. Immunity from artificial sources usually pertains to vaccines directly designed and administered to trigger an immune response, while immunity acquired through intentional exposure might suggest deliberate exposure to a pathogen, which does not align with the broader and more common understanding of natural immunity.