Pertussis: the disease and the vaccine.

Pertussis is a serious respiratory disease in infants. Immunization prevents infection in some; in others it permits infection but prevents disease. Epidemics occur when immunization rates fall. Whole-cell vaccine has proved to be a safe and effective method of disease control. Whole-cell vaccines have been used because the bacterial components responsible for immunity have not been identified. New component vaccines have not been licensed in the United States because they do not meet standards for efficacy. Whole-cell pertussis vaccine has been associated with febrile and afebrile seizures which are generalized and occur within 72 hours of immunization. Permanent brain damage caused by pertussis vaccine is rare. One study suggested a risk of 1:310,000 immunizations which is not precise and probably excessive; however, even using this figure, the risk-benefit ratio for 3 immunizations is favorable when compared to the risks of the natural disease. Child neurologists should recommended immunization for brain damaged infants with static or chronic brain syndromes. Pertussis immunization should be delayed or omitted when the neurologic status is unclear.