Prevention of infectious diseases in older adults through immunization: the challenge of the senescent immune response

A decline in immune function with aging increases the risk of different infectious diseases, many of which of can be prevented by vaccination. Influenza is foremost among these illnesses and remains a significant problem in older adults despite widespread influenza vaccination programs. There are major challenges to developing new or more effective vaccines against influenza and the many other virus and bacterial illnesses that commonly affect the population aged over 65 years. This article will provide a summary of the impact of vaccine-preventable diseases, including influenza, respiratory syncytial virus, pneumococcal disease and herpes zoster, strategies that are being used to develop or improve vaccines against these diseases and how this might alter the immune response to improve protection.