Pertussis can cause serious or even fatal complications.
It can be given to children less than 7 years old. It is given by injection, usually into the arm or the thigh. The pertussis disease is most dangerous to infants and young children, and the vaccine is usually not given to anyone older than 7 years. In most parts of the United States, pertussis immunization is required before starting school. A minimum of three injections should be given, and 5 injections is strongly recommended.