title: Protection of humans against malaria by immunization with radiation-attenuated Plasmodium falciparum sporozoites.
abstract: During 1989-1999, 11 volunteers were immunized by the bites of 1001-2927 irradiated mosquitoes harboring infectious sporozoites of Plasmodium falciparum (Pf) strain NF54 or clone 3D7/NF54. Ten volunteers were first challenged by the bites of Pf-infected mosquitoes 2-9 weeks after the last immunization, and all were protected. A volunteer challenged 10 weeks after the last immunization was not protected. Five previously protected volunteers were rechallenged 23-42 weeks after a secondary immunization, and 4 were protected. Two volunteers were protected when rechallenged with a heterologous Pf strain (7G8). In total, there was protection in 24 of 26 challenges. These results expand published findings demonstrating that immunization by exposure to thousands of mosquitoes carrying radiation-attenuated Pf sporozoites is safe and well tolerated and elicits strain-transcendent protective immunity that persists for at least 42 weeks.
authors.affiliation: Malaria Program, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20850, USA. stephen.hoffman@celera.com
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Hoffman
authors.forename: Lucy M L
authors.initials: LM
authors.lastname: Goh
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Luke
authors.forename: Imogene
authors.initials: I
authors.lastname: Schneider
authors.forename: Thong P
authors.initials: TP
authors.lastname: Le
authors.forename: Denise L
authors.initials: DL
authors.lastname: Doolan
authors.forename: John
authors.initials: J
authors.lastname: Sacci
authors.forename: Patricia
authors.initials: P
authors.lastname: de la Vega
authors.forename: Megan
authors.initials: M
authors.lastname: Dowler
authors.forename: Chris
authors.initials: C
authors.lastname: Paul
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Gordon
authors.forename: Jose A
authors.initials: JA
authors.lastname: Stoute
authors.forename: L W Preston
authors.initials: LW
authors.lastname: Church
authors.forename: Martha
authors.initials: M
authors.lastname: Sedegah
authors.forename: D Gray
authors.initials: DG
authors.lastname: Heppner
authors.forename: W Ripley
authors.initials: WR
authors.lastname: Ballou
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Richie
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D009033:Culicidae / Q000469:parasitology; D004912:Erythrocytes / Q000469:parasitology; D006801:Humans; D007114:Immunization / Q000009:adverse effects; D008288:Malaria / Q000517:prevention & control*; D017780:Malaria Vaccines / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000276:immunology* / Q000528:radiation effects; D014613:Vaccines, Attenuated / Q000276:immunology
chemical_list: D017780:Malaria Vaccines; D014613:Vaccines, Attenuated