Study to Investigate the Induction of an Protective Immune Response to Malaria
The objective of the study is to induce a protective immune response against malaria in healthy human volunteers. The different parts of the immune response will then be studied.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Primary Purpose: Prevention
|Official Title:||Exposure of Human Volunteers to Live Malaria Sporozoites Under Chloroquine Prophylaxis|
- A significant difference in time of thick smear positivity between exposed and control groups
- A significant difference in parasitemia as measured by 18S Pf NASBA between exposed and control group
- A significant difference in kinetics of parasitemia between exposed and control groups as measured by 18S Pf NASBA.
- A difference in occurrence or height of fever between exposed and control groups.
- Significant differences in immune response between exposed and control volunteers (including NK-cell reactivity, TLR reactivity and regulatory T-cell reactivity)
- Significant differences in the outcome of in vitro functional malaria assays between exposed and control volunteers
- Significant differences in cellular reactivity against Pf antigens
- Significant differences in parasite VAR gene expression during infection
- The identification of immune mechanisms that correlate with protection
- 6. The identification of potential vaccine candidates that correlate with protection
|Study Start Date:||January 2007|
|Study Completion Date:||July 2007|
Efforts to develop vaccines against malaria still represent a substantial focus of current research activities. Factors that have hampered the development of a subunit vaccine include the complexity of the malaria life cycle, the wide variety of immune response induced by the malaria parasite, and an incomplete knowledge of protective immunity. This study is therefore aimed at inducing protective immunity against malaria in 15 healthy volunteers. Volunteers will be exposed to the bites of infectious mosquitoes 3 times with live P. falciparum sporozoites under chloroquine prophylaxis. Challenge with infected mosquitoes will be given after stopping chloroquine prophylaxis.
Five volunteers will form a control group; they will be exposed to non-infectious mosquitoes under chloroquine prophylaxis.
Endpoints include the time and height of parasitemia after challenge, the development of fever and immunological parameters.