title: Safety and immunogenicity of a Plasmodium falciparum sporozoite vaccine: boosting of antibody response in a population with prior natural exposure to malaria.
abstract: Recombinant sporozoite vaccine or placebo were administered once to 25 volunteers from an area endemic for malaria. Antibody to R32tet32 rose in 9 of 15 receiving vaccine and remained elevated in 6 for 6 months. Mean absorbance increase was 0.43 +/- 0.40 with vaccine, 0.01 +/- 0.23 with placebo, and 0.72 +/- 0.19 in responders. Six non-responders had significantly lower pre-immunization levels (0.07 +/- 0.05) than responders (0.39 +/- 0.25). There was an association between an increase in immunofluorescence (n = 4) and an increase in absorbance (n = 9) among vaccine recipients (n = 15). Vaccine-induced increase in antibody to natural circumsporozoite antigen was indicated by increases in immunofluorescence and by increases in circumsporozoite precipitation score in 2 of the 5 responders with highest antibody increase measured by enzyme-linked immunosorbent assay. Response to subunit sporozoite vaccine paralleled response to prior natural sporozoite exposure and was significant and prolonged in a population with prior natural exposure to malaria.
authors.affiliation: US Army Medical Research Unit-Kenya.
authors.forename: J A
authors.initials: JA
authors.lastname: Sherwood
authors.forename: C N
authors.initials: CN
authors.lastname: Oster
authors.forename: M
authors.initials: M
authors.lastname: Adoyo-Adoyo
authors.forename: J C
authors.initials: JC
authors.lastname: Beier
authors.forename: G S
authors.initials: GS
authors.lastname: Gachihi
authors.forename: P M
authors.initials: PM
authors.lastname: Nyakundi
authors.forename: W R
authors.initials: WR
authors.lastname: Ballou
authors.forename: A D
authors.initials: AD
authors.lastname: Brandling-Bennett
authors.forename: I K
authors.initials: IK
authors.lastname: Schwartz
authors.forename: J B
authors.initials: JB
authors.lastname: Were
mesh_terms: D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D007113:Immunity, Innate; D007630:Kenya; D008288:Malaria / Q000276:immunology / Q000517:prevention & control*; D008297:Male; D010963:Plasmodium falciparum / Q000276:immunology*; D016052:Protozoan Vaccines / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D013997:Time Factors
chemical_list: D000913:Antibodies, Protozoan; D016052:Protozoan Vaccines; D011994:Recombinant Proteins