Pertussis can cause spells of coughing and choking that make it hard to eat, drink or breathe. The coughing can last for weeks. Pertussis is most dangerous to babies under one year old. Babies with pertussis are so sick, nearly half must go into the hospital. About one baby in 100 with pertussis either dies or is left with permanent brain injury.
Serious illness is less likely in older children and adults.
Polio is a very dangerous disease. Sometimes polio may make it difficult to breathe without the help of a machine. Some people may even die. It causes a high fever, cough, runny nose, sore eyes and rash lasting one or two weeks. Ear infections and pneumonia can also develop.