title: Consistent safety and infectivity in sporozoite challenge model of Plasmodium vivax in malaria-naive human volunteers.
abstract: A safe and reproducible Plasmodium vivax infectious challenge method is required to evaluate the efficacy of malaria vaccine candidates. Seventeen healthy Duffy (+) and five Duffy (-) subjects were randomly allocated into three (A-C) groups and were exposed to the bites of 2-4 Anopheles albimanus mosquitoes infected with Plasmodium vivax derived from three donors. Duffy (-) subjects were included as controls for each group. Clinical manifestations of malaria and parasitemia were monitored beginning 7 days post-challenge. All Duffy (+) volunteers developed patent malaria infection within 16 days after challenge. Prepatent period determined by thick smear, was longer for Group A (median 14.5 d) than for Groups B and C (median 10 d/each). Infected volunteers recovered rapidly after treatment with no serious adverse events. The bite of as low as two P. vivax-infected mosquitoes provides safe and reliable infections in malaria-naive volunteers, suitable for assessing antimalarial and vaccine efficacy trials.
authors.affiliation: Instituto de Inmunología, Universidad del Valle, Cali, Colombia. sherrera@inmuno.org
authors.forename: Sócrates
authors.initials: S
authors.lastname: Herrera
authors.forename: Yezid
authors.initials: Y
authors.lastname: Solarte
authors.forename: Alejandro
authors.initials: A
authors.lastname: Jordán-Villegas
authors.forename: Juan Fernando
authors.initials: JF
authors.lastname: Echavarría
authors.forename: Leonardo
authors.initials: L
authors.lastname: Rocha
authors.forename: Ricardo
authors.initials: R
authors.lastname: Palacios
authors.forename: Oscar
authors.initials: O
authors.lastname: Ramírez
authors.forename: Juan D
authors.initials: JD
authors.lastname: Vélez
authors.forename: Judith E
authors.initials: JE
authors.lastname: Epstein
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Richie
authors.forename: Myriam
authors.initials: M
authors.lastname: Arévalo-Herrera
mesh_terms: D000328:Adult; D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use; D002738:Chloroquine / Q000627:therapeutic use; D004375:Duffy Blood-Group System; D005260:Female; D005334:Fever; D006801:Humans; D016780:Malaria, Vivax / Q000469:parasitology / Q000635:transmission*; D008297:Male; D008875:Middle Aged; D018512:Parasitemia; D010966:Plasmodium vivax / Q000276:immunology* / Q000502:physiology*; D011319:Primaquine / Q000627:therapeutic use; D011897:Random Allocation; D034101:Sporozoites / Q000276:immunology* / Q000502:physiology; D055815:Young Adult
chemical_list: D000962:Antimalarials; D004375:Duffy Blood-Group System; D002738:Chloroquine; D011319:Primaquine