Innate immunity is not caused by an infection or vaccination.

The claim states that innate immunity is not caused by an infection or vaccination. Innate immunity constitutes the body's baseline, non-specific host defense mechanisms, which are constantly active and regulated by physiological factors, microbiota-derived metabolites, and endogenous danger signals (DAMPs) rather than requiring an external pathogen or vaccine trigger. The retrieved literature (such as papers 4, 5, and 6) supports the understanding that innate immune programs, barrier homeostasis, and trained immunity are maintained and triggered by non-infectious endogenous cues, epigenetic inputs, and sterile tissue signals. Therefore, the claim is supported by current immunological science.