Influenza Vaccination May Combat Inflammaging Through 'Trained Tolerance' Mechanism

An intriguing review in Ageing Research Reviews suggests influenza vaccination might combat inflammaging—chronic low-grade inflammation that drives many age-related diseases—through a mechanism called 'trained tolerance.' Rather than simply preventing flu, vaccines may reprogram innate immune cells to respond more appropriately to inflammatory triggers. This matters because inflammaging contributes to cardiovascular disease, neurodegeneration, diabetes, and frailty. If routine vaccinations provide broader anti-inflammatory benefits beyond their intended targets, they could represent an unexpectedly powerful and accessible longevity intervention already widely used. The 'trained immunity' concept—where vaccines create lasting changes in innate immune function—has gained traction recently, but 'trained tolerance' (dampening excessive inflammation) is less studied. The hypothesis draws on emerging evidence that certain vaccines have 'heterologous effects,' influencing health outcomes beyond the targeted pathogen. However, this is primarily a mechanistic review rather than presenting new clinical data. The key question is whether observational associations between vaccination and better aging outcomes reflect this mechanism or simply healthier people getting vaccinated. Randomized trials specifically measuring inflammatory markers and age-related outcomes in vaccinated versus unvaccinated older adults would be needed to confirm this promising hypothesis.