Background: Pertussis toxin (PT) stimulates IgE production in animals, and pertussis vaccination and whooping cough may have similar effects in man.
Methods: We analyzed IgE responses to PT (PT-IgE) in sera from children primarily immunized with three doses of either an acellular 2- or 5-component vaccine, or a whole-cell (Wc) pertussis vaccine, and in children after whooping cough. The study comprised 50 children with both atopic disease and positive skin prick test, 99 nonatopic controls, and 40 children with verified pertussis.
Results: Immunoglobulin E antibodies against PT were demonstrated in 19% and 24% of sera from vaccinated children at 7 and 12 months, respectively, and in 9% at 2.5 years. At 7 months, PT-IgE was more common after vaccination with acellular (24%) than with the Wc vaccine (3%, P = 0.02). PT-IgE was also more common (P = 0.001) after vaccination in children classified as atopic (36%) than in the control group (10%). Thirty percent of the children with pertussis had PT-IgE, more often so in atopic than nonatopic children (P = 0.02).
Conclusions: Transient production of PT-IgE seems to be common after primary pertussis immunization with acellular vaccines, and after whooping cough, particularly in atopic subjects.