The immune system becomes less able to detect malignant cells, and cancer risk increases with age. The immune system also becomes less able to detect foreign particles, and infection risk is greater. Other things also increase the risk of infections. Having an illness or surgery can further weaken the immune system, making the body more susceptible to subsequent infections. Besides slightly decreased immunity, aging also affects inflammation and wound healing.
Many older people heal slower and have more problems with healing.
This may be directly related to changes in the immune system, or it may be a consequence of other problems such as diabetes or arteriosclerosis. Just as routine immunizations are important to prevent illness in children, a few routine immunizations are important as we get older. These optional immunizations are not necessary for ALL older people, but are appropriate for some. Keeping generally healthy also helps. Exercise , eat right, reduce or stop smoking , and minimize alcohol use .