The Committee to Advise on Tropical Medicine and Travel (CATMAT) and the National Advisory Committee on Immunization (NACI). Travel, influenza, and prevention.

Influenza infection causes fever, sore throat, muscle pains, cough, lassitude and headache. Annual attack rates average 10% to 20%, but may be higher during severe epidemics. Malaise following influenza can persist for several weeks. Morbidity and mortality, associated with influenza, are usually more common in the older population and in individuals with significant concurrent medical problems. These latter groups have been traditionally targetted for the immunization programs.