Vaccination, immunization, inoculation; call it what you like, it’s the process of activating the human immune system by the injection of a specialized chemical preparation into a host. The human immune system is stimulated to the maximum during the first five years of life when newborns and toddlers receive multiple injections of 15 different vaccines. The schedule of immunizations eases gradually over the teen years until after age 18 (adulthood) when it narrows down to annual flu and COVID vaccines, shingles vaccine, and vaccinations that are given in response to disease exposure or prior to overseas travel.
After age 18, the immune system isn’t “challenged” as frequently, and at a certain point begins to lose its effectiveness. It doesn’t become dormant, by any means, but it gradually loses potency as we reach our 70’s and 80’s. The process of the aging of our immune system is called Immunosenescence. It means our immune system changes biologically and isn’t functioning maximally as it had been up until later in life. In this state, our bodies are more susceptible to infectious invaders and chronic diseases worsen more easily. The system needs re-invigorating, re-activation, and the administration of vaccines helps keep the system finely tuned.
Spanish researchers have shown that vaccination has a role in slowing immunosenescence. Vaccines don’t reverse biological aging of the immune system, but they increase activation of natural immune response and preserve the immune system function. Their major impact is to give the elderly a better ability to resist functional decline. They have also been shown to reduce cardiovascular events and reduce hospitalizations for cardiovascular disorders.
“Vaccination should be considered a key preventive intervention not only against infections, but also against cardiovascular events and clinical decompensation.” They, thus, promote immunofitness which improves our ability to resist the tendency to be overcome by the unhealthy aspects of aging. Vaccination doesn’t slow aging of the immune system, but instead it preserves immune system function. For this to be successful, it also requires we exercise, get adequate restorative sleep, reduce stress, practice good nutrition, and manage chronic diseases carefully.
Bottom Line: Periodic vaccinations (like influenza, COVID-19) re-awaken our slumbering, aging immune systems, promote immunofitness, and delay immunosenescence.
Reference: Sierra C. Immunofitness: Vaccination for Healthy Aging. Medscape 2026 March 11.
