Comparison of a Three-Component Acellular Pertussis Vaccine With a Whole-Cell Pertussis Vaccine in 15- Through 20-Month-Old Infants

Objctiv. To compare the immunogenicity and reactogenicity of a diphtheria and tetanus toxoids and three-component acellular pertussis vaccine (DTaP) with a diphtheria and tetanus toxoids and wholecell pertussis vaccine (DTwP) when administered as a booster dose to infants 15 through 20 months of age. Design. Randomized, double-blind, comparative study. Setting. Three pediatric practices (two private; one hospital-based). Participants. One hundred and sixty-five healthy 15-through 20-month old infants. Selection procedures and interventions. Infants were randomly assigned in a 2:1 ratio to receive vaccine from a single lot of DTaP or from commercially available DTwP