title: Enhanced memory B-cell immune responses after a second acellular pertussis booster vaccination in children 9 years of age.
abstract: Whooping cough has made its comeback and the incidence of pertussis in countries with widespread pertussis vaccination is most prominent in individuals above 9 years of age. To control the burden of infection, several countries already introduced acellular pertussis (aP) booster vaccination in adolescents and/or adults. However, antibody levels wane rapidly after vaccination even at older age. In this longitudinal study we investigated the effect of a second aP booster on the pertussis-specific memory B-cell immunity in children 9 years of age that have previously been vaccinated according to the national immunization program. Longitudinal blood samples were taken before, one month and one year after the booster. Purified B-cells were polyclonally stimulated and frequencies of memory B-cells were identified by ELISPOT-assays specific for various pertussis antigens. In addition, IgG levels and avidity indices were measured with fluorescent bead-based multiplex immunoassays. Starting with low pertussis-specific antibody and memory B-cell levels, a typical booster response was measured at one month after vaccination with increased antibody and memory B-cell responses. Although these responses declined slightly after one year, they substantially exceeded pre-booster levels and the avidity indices of the anti-pertussis antibodies remained high. Furthermore, high numbers of pertussis-specific memory B-cells at one-month post-booster correlate quite reliably with the corresponding high antibody response at one-year follow-up. In conclusion, booster vaccination in children 9 years of age induced an enhanced pertussis-specific memory immune response that sustained at least for one year. Therefore, this study supports the introduction of booster vaccination in older age groups.
authors: Centre for Infectious Disease and Control (Cib), National Institute for Public Health and the Environment, Bilthoven, The Netherlands. Lotte.Hendrikx@rivm.nl
authors: Lotte H
authors: LH
authors: Hendrikx
authors: Mariet K
authors: MK
authors: Felderhof
authors: Kemal
authors: K
authors: Oztürk
authors: Lia G H
authors: LG
authors: de Rond
authors: Marlies A
authors: MA
authors: van Houten
authors: Elisabeth A M
authors: EA
authors: Sanders
authors: Guy A M
authors: GA
authors: Berbers
authors: Anne-Marie
authors: AM
authors: Buisman
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D000915:Antibody Affinity; D001402:B-Lymphocytes / Q000276:immunology*; D002648:Child; D058501:Enzyme-Linked Immunospot Assay; D006801:Humans; D007117:Immunization, Secondary / Q000379:methods*; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory; D008137:Longitudinal Studies; D010567:Pertussis Vaccine / Q000008:administration & dosage / Q000276:immunology*; D022282:Vaccines, Acellular / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D010567:Pertussis Vaccine; D022282:Vaccines, Acellular