Vaccination boosts adult immunity to varicella zoster virus

The Efficacy of Vaccines to Prevent Infectious Diseases in the Elderly

Infectious diseases still represent a major challenge to human progress and survival. Especially elderly persons are more frequently and severely affected by infectious diseases and they display distinct features with respect to clinical presentation and treatment. Although vaccinations are considered a vital medical procedure for preventing morbidity and mortality caused by infectious diseases, the protective effect of vaccinations is abrogated in elderly persons. This is due to a decline in the functions of the immune system referred to as immunosenescence. The first part of this chapter will therefore summarize the status quo of the efficacy of vaccines in preventing morbidity and mortality caused by typical infectious diseases in the elderly, such as influenza, pneumonia and tuberculosis. The second part will then elucidate the underlying age-related mechanisms which may contribute to the decreased efficacy of vaccines. Based on the complex mechanisms involved in immunosenescence, strategies will be outlined which may be succesfful in enhancing protective immune responses following vaccination in elderly persons.

Immunizations in the elderly: do they live up to their promise?

In the 21st century, public health is not only challenged by newly emerging and re-emerging infectious diseases but also by demographic developments that are taking place in many countries. Importantly, infections in the elderly are more frequent, more severe and have distinct features with respect to clinical presentation and treatment. This is due to a decline in the functions of the immune system referred to as immunosenescence. The most important age-related changes affect the T cell system. Although this derogates the protective effect of some vaccines, vaccinations are still considered the most cost-effective medical procedure for preventing morbidity and mortality caused by infectious diseases. The present article aims at outlining the impact of infectious diseases on the elderly and summarizing the progress made in the field of vaccinations of the elderly and how age-related changes within the immune system contribute to the decreased efficacy of vaccines.