Chemoprophylaxis and Plasmodium Falciparum NF54 Sporozoite Immunization Challenged by Heterologous Infection
Status:
Completed
Trial end date:
2015-11-01
Target enrollment:
Participant gender:
Summary
Malaria, a disease caused by the parasite Plasmodium, is one of the world's major infectious
diseases. With approximately 627.000 deaths a year, it is both a chief cause of morbidity and
mortality as well as a significant contribution to ongoing poverty in endemic countries.
Ultimately, the key to malaria control, and hopefully eradication, would be an effective
vaccine. Though a number of vaccine-candidates have entered the pipeline of pre-clinical and
clinical development, they have yet to achieve the level of efficacy necessary for effective
malaria prevention. It has been shown previously that if healthy human volunteers taking
chloroquine chemoprophylaxis are repeatedly exposed to Plasmodium parasites through the bites
of infected mosquitoes, they are fully protected against a later challenge infection with a
'homologous' (genetically similar) Plasmodium parasite. This process is known as
ChemoProphylaxis and Sporozoites, or CPS-immunization. One of the obstacles to developing an
effective vaccine is the genetic heterogeneity of malaria parasites. To further consider the
development of whole-parasite based vaccines against malaria and in order to better
understand the protective immunity induced by CPS-immunization, it is essential to
investigate whether heterologous protection against genetically diverse (heterologous) P.
falciparum clones can be induced.
This is a single center, randomized, double-blind study to determine whether healthy
volunteers immunized with P. falciparum NF54 parasites under chloroquine prophylaxis are
protected against a challenge infection with the genetically distinct NF135.C10 or NF166.C8
P. falciparum clones.
Phase:
N/A
Details
Lead Sponsor:
Radboud University
Collaborator:
Bill and Melinda Gates Foundation
Treatments:
Atovaquone Atovaquone, proguanil drug combination Chloroquine Chloroquine diphosphate Proguanil Vaccines