Immunogenicity and reactogenicity of a reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine in healthy Taiwanese children and adolescents

Purpose: Disease caused by Bordetella pertussis is increasingly being identified among older children and adults in immunized populations, indicating a waning of the vaccine-induced immunity. These findings suggest the need for booster immunization of older children and adults. Modern acellular reduced-antigen-content vaccines have been developed, which can be given as a booster in individuals more than 4 years of age. This study was to assess the immunogenicity and reactogenicity of Boostrix™, GlaxoSmithKline Biologicals' reduced-antigen-content diphtheria-tetanus acellular pertussis (dTpa) vaccine, when administered as a booster in healthy subjects previously primed with DTP vaccine. Methods: Healthy Taiwanese children and adolescents aged 6-8 years and 15-20 years, previously primed with DTP vaccine, were enrolled. All received one dose of Boostrix™. Two blood samples were taken from each of them, one before vaccination and one at 1 month after vaccination. Serum antibodies to diphtheria and tetanus toxoids and immunoglobulin G (IgG) antibodies against the pertussis components PT, FHA and PRN were measured by enzyme-linked immunosorbent assay (ELISA) technique. Adverse reactions following vaccination were recorded. Results: A total of 180 subjects were recruited. The vaccine response rates to the pertussis antigens ranged between 89.0-100%. There were no serious adverse events reported during the study period. Conclusions: The results of this study suggest that Boostrix™ may be safely and effectively administered as a booster dose to children previously primed with DTP vaccine.