Influenza Vaccine in the Elderly and Chronic Obstructive Pulmonary Disease.

Influenza viruses are RNA viruses that are a major determinant of morbidity and mortality caused by respiratory disease. Influenza is highly contagious and has caused epidemics and pandemics for centuries. Most influenza infections are self- limited, but lower respiratory tract and cardiac complications can result in increases in hospitalizations and deaths. The recommended composition of influenza vaccine is updated annually in order to provide a vaccine that is antigenically well matched with the new influenza virus strains that are expected to cause epidemics. Influenza vaccination significantly reduces mortality; however, approximately one third of elderly Americans are not immunized annually. The nation's goal is to increase the influenza vaccination rate among the elderly to 90%. Vaccination is the most effective measure for reducing the impact of influenza and is a cost-effective preventive health intervention for the elderly and individuals with chronic obstructive pulmonary disease.