Whooping cough is a respiratory disease caused by Bordetella pertussis. Since the 1950s in developed countries
pertussis vaccinations are included in the national immunization program. However, antibody levels rapidly wane after both whole cell and acellular
pertussis vaccination. Therefore protection against
pertussis may depend largely on long-term B- and T-cell immunities. We investigated long-term
pertussis-specific memory B-cell responses in children who were primed at infant age with the Dutch wP-
vaccine (ISRCTN65428640). Purified B-cells were characterized by FACS-analysis and after polyclonal stimulation memory B-cells were detected by ELISPOT-assays specific for
pertussis toxin, filamentous haemagglutinin,
pertactin and
tetanus. In addition, plasma
IgG levels directed to the same
antigens were measured by a fluorescent bead-based multiplex immunoassay. Two and 3 years after wP priming as well
as 2 and 5 years after the aP booster at the age of 4, low plasma
IgG levels to the
pertussis proteins were found. At the same time, however
pertussis protein-specific memory B-cells could be detected and their number increased with age. The number of
tetanus-specific memory B-cells was similar in all age groups, whereas
IgG-
tetanus levels were high 2 years after
tetanus booster compared to pre- and 5 years post-booster levels. This study shows the presence of long-term
pertussis protein-specific memory B-cells in children despite waning antibody levels after vaccination, which suggests that memory B-cells in addition to
antibodies may contribute to protection against
pertussis.