Safety and Immunogenicity of an Acellular Pertussis Vaccine Booster in 15- to 20-Month-Old Children Previously Immunized With Acellular or Whole-Cell Pertussis Vaccine as Infants

The objective of this study was to evaluate reactogenicity and immunogenicity of the recently US-licensed Connaught/BIKEN (C/B) acellular DTP (ADTP) vaccine as a booster for children aged 15 to 20 months after they had received either the C/B ADTP or the US-licensed Connaught whole-cell DTP (WDTP) vaccine as infants. After infants had received either three doses of C/B ADTP (n=109) or three doses of WDTP vaccine (n=30) at 2, 4, and 6 months of age according to a 3:1, randomized, prospective design, they all received booster doses at 15 to 20 months of age with C/B ADTP. Fever >101 o F (38.3 o C), irritability, injection site redness ≥1 inch, injection site swelling, and injection site pain, among other reactions, were monitored for 14 days after vaccination