Pneumonia is an infection of the lungs that can cause mild to severe life threatening illness in people of all ages. It may be treated with respiratory therapies and medications and can sometimes be prevented with vaccines. According to the Centers for Disease Control and Prevention, pneumonia is the leading infectious cause of death in children younger than 5 years old worldwide. Vaccines available in the U.S. include pneumococcal (Prevnar and Pneumovax)  Hemophilus influenza type b (HIB), Pertussis (whooping cough)  and Influenza (flu). Risk increases with factors that decrease resistance such as old age, diabetes, heart disease, use of immunosuppressing medications and certainly smoking as well as exposure to others with respiratory illness.