Consistent safety and infectivity in sporozoite challenge model of Plasmodium vivax in malaria-naive human volunteers

Am J Trop Med Hyg. 2011 Feb;84(2 Suppl):4-11. doi: 10.4269/ajtmh.2011.09-0498.


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.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Animals
  • Antimalarials / therapeutic use
  • Chloroquine / therapeutic use
  • Duffy Blood-Group System
  • Female
  • Fever
  • Humans
  • Malaria, Vivax / parasitology
  • Malaria, Vivax / transmission*
  • Male
  • Middle Aged
  • Parasitemia
  • Plasmodium vivax / immunology*
  • Plasmodium vivax / physiology*
  • Primaquine / therapeutic use
  • Random Allocation
  • Sporozoites / immunology*
  • Sporozoites / physiology
  • Young Adult


  • Antimalarials
  • Duffy Blood-Group System
  • Chloroquine
  • Primaquine