Pertussis agglutinins in vaccinated children: better response with adjuvant.

Children were immunized with a single batch of pertussis vaccine, either adsorbed on aluminium hydroxide or plain. With a primary course of three injections, adsorbed vaccine produced higher titres of pertussis agglutinins in the serum than did plain vaccine. There was no obvious difference in response between those who received the three doses at intervals of 1-2 months, starting at 3-4 months of age, and those in whom the third dose was delayed until about 6 months after the second, but the number of children in each group was small.