Plasmodium knowlesi is now established as the fifth Plasmodium species to cause malaria in humans.
We investigated here the hypothesis that the delayed acquisition of immunity to malaria could be related to a worm-induced Th2 drive on antimalarial immune responses.
In conclusion, malaria-naive volunteers can be safely and reproducibly infected with bites of 2–10 An. albimanus mosquitoes carrying P. vivax sporozoites. This challenge method is suitable for vaccine and anti-malarial drug testing.