title: Reduced antibody responses against Plasmodium falciparum vaccine candidate antigens in the presence of Trichuris trichiura.
abstract: BACKGROUND
  Helminth infections are highly prevalent in the tropics and may have an effect on immune responses to vaccines due to their immunomodulatory effect. The prevalence of helminth infections in young children, the target group for malaria and most other vaccines, is high. Therefore we assessed the influence of helminth infection on vaccine-induced immune responses in a phase I clinical trial of the malaria vaccine candidate GMZ2.
  
  
  METHODS
  Twenty Gabonese preschool-age children were vaccinated with GMZ2, a blood stage malaria vaccine candidate. Humoral immune response against the vaccine antigens and parasitological status were assessed. Vaccine-specific antibody concentrations and memory B-cell numbers were compared in worm infected and non-infected participants.
  
  
  RESULTS
  Antibody response to GMZ2 was 3.4-fold (95% confidence interval: 1.6, 7.4) higher in Trichuris trichiura negative subjects compared to positive participants, whereas immunoglobulin subclass distribution was similar. Memory B-cell response was moderately increased in T. trichiura negative individuals, although the difference was not significant.
  
  
  CONCLUSIONS
  Future malaria vaccine development programs need to account for worm-mediated hyporesponsiveness of immune reactions.
authors.affiliation: Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.
authors.forename: Meral
authors.initials: M
authors.lastname: Esen
authors.forename: Benjamin
authors.initials: B
authors.lastname: Mordmüller
authors.forename: Pablo Martinez
authors.initials: PM
authors.lastname: de Salazar
authors.forename: Ayola Akim
authors.initials: AA
authors.lastname: Adegnika
authors.forename: Selidji Todagbe
authors.initials: ST
authors.lastname: Agnandji
authors.forename: Frieder
authors.initials: F
authors.lastname: Schaumburg
authors.forename: Aurore Bouyoukou
authors.initials: AB
authors.lastname: Hounkpatin
authors.forename: Sina
authors.initials: S
authors.lastname: Brückner
authors.forename: Michael
authors.initials: M
authors.lastname: Theisen
authors.forename: Sabine
authors.initials: S
authors.lastname: Bélard
authors.forename: Ulysse Ateba
authors.initials: UA
authors.lastname: Ngoa
authors.forename: Saadou
authors.initials: S
authors.lastname: Issifou
authors.forename: Maria
authors.initials: M
authors.lastname: Yazdanbakhsh
authors.forename: Peter G
authors.initials: PG
authors.lastname: Kremsner
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D017780:Malaria Vaccines / Q000008:administration & dosage / Q000276:immunology*; D010963:Plasmodium falciparum / Q000276:immunology*; D014257:Trichuriasis / Q000276:immunology*; D014258:Trichuris / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D017780:Malaria Vaccines