Load bearing exercise is known to help maintain strong bones as we age. Physical exercise prevents muscle atrophy and promotes overall body and organ health. It is also known that cognitive exercises and social interaction help to strengthen the brain against age-related degenerative effects.
These are just a few examples, but "Use it or lose it" seems to be a common refrain in the human body.
As children and youths our immune systems are subject to a regular battery of challenges as they acclimatise to the miasma of pathogens in our environment, but as we age the frequency of novel immune system challenges decreases.
Have there been any investigations of whether regular vaccinations, particularly among those who may travel frequently and require additional immunization for a broader array of pathogens, or perhaps even simply additional regular boosters beyond what would normally be prescribed, have any effect on age-related decline of the immune system response?
Naturally, becoming actually infected with many real pathogens would be overwhelmingly deleterious, on balance, but is there any merit to the idea that the benign "exercise" of a vaccine-induced immune response confers some benefit in terms of slowing the natural decline in immune response? Have any long term studies been done to this effect?
By request, I'll add some additional detail.
- Immune System aging is a known, if not fully understood phenomenon.
- Geriatric patients require high dose vaccines to produce a sufficient immune response
- Load bearing exercise has some benefit for bone mineral density in aging populations
- Physical exercise is beneficial for many aspects health (do we really need an exhaustive reference list for this?)
- Cognitive stimulation is beneficial for the prevention and treatment of dementia, cognitive decline.
The first linked paper above discusses potential pharmacological routes to fortifying the immune system, and briefly discusses other lifestyle changes such as caloric restriction, which it notes may confer some benefit, but this question is interested primarily in the influence of the history of frequency and diversity of direct immune system challenges on geriatric immune system response decline.
I did spend a bit of time digging through papers to try to find something on this topic, but medicine is a rather foreign field to me so mostly I'm curious to know if anyone is aware of any, even small, studies that have measured immune response in older patients to determine any correlation to the frequency or variety of vaccines they were exposed to during their lives.
Those with a broad travel history may also have exposure to a wider variety of novel immune system challenges than those who remain more geographically isolated or even spend more of their adult lives indoors and away from immune stressors. Tangentially, does the geriatric immune response decline more rapidly in those whose adult lives are largely insulated from pathogens (living in a sterile, controlled indoor environment, etc)?
Or perhaps more to the point, is there any known correlation between the frequency of novel immune system challenges and the strength of immune response in the aging population?