The aim of this study was to compare
pertussis-specific humoral and cellular immunity in children 5 years after a primary vaccination with a combined
diphtheria,
tetanus, tricomponent acellular
pertussis, and
hepatitis B vaccine (
DTaP-HBV;
InfanrixHepB; SmithKline Beecham) with immunity after natural
infection. The subjects were 38 children aged 5 to 6 years who received
DTaP-HBV at 3, 5, and 11 months of life and 21 subjects of similar ages and sex who acquired
pertussis in the first year of life.
Immunoglobulin G (
IgG) antibody titers against Bordetella pertussis
antigens, peripheral blood mononuclear cell-specific proliferation, and the secretion of
cytokines were evaluated. After 5 years, only a small proportion of vaccinated and infected children had significant specific concentrations of
IgG in serum against all three B.
pertussis antigens, and T-cell responses persisted in a minority of subjects. A preferential type 1
cytokine response with the secretion of
gamma interferon was observed in the
pertussis group, whereas a type 2 skewed response was observed in the vaccinated children; however, the quantitative differences in the
cytokines produced by
DTaP-HBV and natural
infection were minimal. In conclusion, our results show that the immune responses induced by primary
pertussis vaccination are qualitatively and quantitatively similar to those seen in children who recovered from natural
infection and highlight the need for booster immunization with
pertussis vaccines in order to maintain adequate levels of a specific immune response to B.
pertussis.