Characterization of the febrile response to diphtheria-tetanus-pertussis vaccination

To evaluate the incidence and course of fever following DTP vaccination we prospectively studied 430 healthy infants who received the four doses of vaccine at ages 2, 4, 6 and 12 months. Each infant was followed one week before and three days after immunization. Mothers were instructed to record rectal temperature every six hours after each vaccine dose for a minimum of seven measurements (including baseline). After all vaccine doses, body temperature peaked at 12 hours and decreased steadily thereafter. The highest temperature was observed after the fourth dose. A temperature of 38°C or higher was found in 47.1, 55.7, 56.7 and 49.8% of doses 1 to 4, respectively. Fever following DTP vaccination appears in approximately half of the infants, peaks 12 hours after vaccination, and is highest after the fourth dose. Physicians should know the characteristics of the febrile reaction to successive doses of DTP vaccine and inform parents accordingly.