Natural immunity is immunity that has been inherited in contrast to one that has been acquired. If an individual acquires immunity by being exposed to a virus via natural contact/exposure, as opposed to having the virus introduced via the blood stream as the result of vaccination (un-natural), then that individual is said to have natural immunity.
Immunity is the body’s ability to recogonise,resist attack or overcome infection by invading microbes, viruses or parasites.
Immunity is based on the proper functioning of the body’s immune system. Cells, cell products, organs, and structures of the body involved in the detection and destruction of foreign invaders, such as bacteria, viruses, and cancer cells. Immunity is based on the immune system’s ability to launch a defense against such invaders.
For the system to function properly, it must be able to distinguish between the material of its own body (self) and material that originates outside of it (nonself). Failure to make this distinction can result in autoimmune diseases.
In natural or innate immunity, immune mechanisms present at birth, (inheirted from the dam and then obtained through nursing) work against a wide variety of microbes whether or not they have ever been encountered before.
Would you like to learn more about natural immunity and how it works? There is an entire chapter in the book: Natural Rearing: Breeding & Raising Dogs The Way Nature Intended and the online course – A Better Understanding of Vaccines goes into wonderful detail.