Abstract
Complex changes of the innate and adaptive immune system occur in old age and contribute to the increased frequency and severity of infections in older adults. At the same time, chronic, subclinical inflammation occurs, which promotes age-related diseases. Age-associated changes in the immune system also influence the formation, growth and metastasis of malignant tumors. Furthermore, there are indications that the aging of the immune system contributes to the development of autoimmunity. Vaccinations are an important preventive measure for maintaining health and improving the quality of life, not only but especially in old age. The development of optimized and new vaccines for the older population has made great progress in recent years and decades; however, vaccination rates among older adults are well below target for all vaccinations.