Influenza Infection in the Elderly
Influenza is a febrile respiratory disease, which is usually associated with a mild acute self-limited illness. However, certain risk factors, including ageing, are associated with severity of disease and the occurrence of influenza-related complications. Influenza infection has shown to be foremost among all infectious diseases in its association with an age-related increase in the incidence of serious complications. A decrease in immune function is a hallmark of ageing that imposes negative effects in its ability to resist influenza virus infection and its response to vaccination. It has been recognized that the ageing process affects both branches of the immune system, namely, the innate and adaptive immune systems.