Influenza (flu) is an acute respiratory infectious disease caused by influenza virus. Clinically, it manifests as sudden fever, muscle aches and mild respiratory symptoms, with a short course and self-limiting. It can break out locally or become widespread. Elderly influenza patients are prone to pneumonia, and the prognosis is often more serious for those who are old, weak or have cardiopulmonary diseases. The incidence rate is higher in people over 60 years old, and the condition is more serious. The death rate of the elderly due to infection with this virus is higher than that of other ages. The elderly, children and patients with chronic diseases should be the key groups for the prevention and control of seasonal influenza.