Immune System Training

Trained immunity differs from adaptive immunological memory because it is not antigen-specific. Historically rising rates of autoimmune disease correlate with increasingly aseptic modern environments including less outdoor time, reduced soil contact, and excessive hand sanitizer use. The article identifies mechanistic studies of trained immunity from respiratory vaccines as a future research priority. Normal, repeated exposure to pathogens is essential for immune system development and resilience. Trained immunity is proposed as the predominant mechanism for respiratory vaccine non-specific effects. Non-specific effects appear across both live attenuated and inactivated vaccines. Further research is needed to determine whether vaccine type or vaccination status itself drives non-specific effects. After approximately six months of regular pathogen exposure, individuals stop getting sick at the same rate because the immune system has been trained to respond efficiently. Chronic over-sanitization and elimination of microbial exposure prevents immune calibration, resulting in weaker and more autoimmunity-prone immune responses.