Is an acute, contagious bacterial disease, characterized by fever, malaise, sore throat, hoarseness and formation of thick gray membrane covering the throat and tonsils, which may obstruct breathing. In some cases paralysis of the respiratory muscles develops and causes death. Immunization with a very effective vaccine is available ( usually as combined with whooping cough and tetanus vaccines, DTP for children) A booster shot every 10 years is appropriate ( 5 years for travelers), usually given combined with tetanus vaccine ( Adult TD).