Abstract

A prospective study of minor reactions after the four combined vaccinations for diphtheria, tetanus, pertussis, and poliomyelitis (DTPP) was performed in 540 infants in the Netherlands. An analysis was made of the symptoms observed by the infants' parents after 2026 inoculations. The aim was to assess the frequency, association, and risk of recurrence of minor reactions. These were designated as fever (greater than or equal to 38.0 degrees C), local reactions, crying, and other general symptoms (changes in sleeping or eating patterns, vomiting, drowsiness, fretfulness). Fever occurred after 67.7% of inoculations, one or more local reactions after 66.2%, and increased crying after 64.4%. After 80% of inoculations, one or more other general symptoms occurred. Only 4.4% of inoculations were followed by no minor reaction. Fever rarely occurred as an isolated symptom; it showed a significant association (i) with one or more local reactions, (ii) with increased crying, and (iii) with two or more other general symptoms. Chances of fever, redness at the inoculation site, and crying after inoculation increased with repeat inoculations if these reactions had occurred after preceding inoculation(s).