Ageing and respiratory infections: The airway of ageing

• Respiratory infections lead to high mortality and morbidity among older adults.
• Ageing is associated with a decline in immune function termed ‘immunosenescence’.
• Immune senescence is associated with poor vaccine efficacy.
• Effective vaccines need to be developed for better protection for the elderly.

Respiratory infections are a leading cause of infectious disease burden worldwide especially among the elderly. Furthermore, a direct relationship between ageing and susceptibility to infections has been reported, which may be caused by impaired immune function, frailty and degree of exposure to infectious diseases. Many complex changes, including structural and age-associated decline in immunity are associated with increased pulmonary diseases worldwide and result in a high age-related disease burden. The common respiratory infections that present serious risks for the elderly include influenza, respiratory syncytial virus, and a number of bacterial pathogens including pneumococcus and tuberculosis. Vaccines are available for a limited number of these pathogens including influenza, pneumococcal and pertussis vaccines. This mini review article examines the age-related changes in immune function that predispose the elderly population to respiratory infections and potential loss of vaccine efficacy with a focus on ageing and influenza infections.