Malaria is a disease that affects many people in Africa and in Mali. It is caused by germs that are spread by mosquito bites. This study will look at the safety, effectiveness, and best dose of an experimental malaria vaccine in people who are regularly exposed to malaria. Study participants will be 60 adults, 18-55 years old, who live in Bandiagara, Mali. Volunteers will get either 3 full doses of the experimental malaria vaccine, 3 half doses of the malaria vaccine, or a rabies vaccine that has been approved in Mali. (Rabies is an infection of the brain that usually causes death, and can be caught from being bitten by infected dogs or bats.) The 3 vaccinations will be given by injection into the upper arm 30 days apart. Volunteers will be enrolled in the study for approximately 12 months after the first vaccination. Volunteers will have 14 blood samples collected during the study for testing to make sure that the vaccine is not harmful and to measure the effect of the vaccine.
| Estimated Enrollment: |
60 |
| Study Start Date: |
November 2004 |
| Estimated Study Completion Date: |
December 2005 |
The primary objective of this study is to evaluate the safety and reactogenicity of two dose levels of WRAIR's AMA1 malaria antigen (FMP2.1) adjuvanted in GlaxoSmithKline Biologicals' AS02A compared to rabies vaccine in malaria-experienced Malian adults aged 18-55 years inclusive. Secondary objectives are to: (1) measure the magnitude and duration of antibody response to FMP2.1; (2) measure cellular immune responses to FMP2.1 at baseline and after immunization; (3) measure the inhibition of parasite growth by the in vitro GIA; and (4) determine the specificity of the antibodies to diverse AMA1 genotypes in addition to 3D7, by measuring by ELISA, and GIA on parasites with typed AMA1. A double-blind controlled dose escalation trial will allow assessment of vaccine safety in each of three groups, one group each to receive medium and full dose levels of the experimental vaccine, and one group to receive the comparator vaccine. Thirty adults will be randomized to receive the medium dose level of FMP2.1 (n=20) or rabies vaccine (n=10) and thirty to receive the full dose level of FMP2.1 (n=20) or rabies vaccine (n=10). The division of the rabies group into two groups of ten is done to maintain blinding at each immunization time point, and all participants who receive the rabies vaccine will be analyzed as a single group. The sample size of the groups, however, will not allow detection of anything other than very large differences in the occurrence of adverse events among the three groups. The advantage of double blinding is to remove the potential for investigator and participant prejudgment about the effects of the vaccines in the reporting of adverse events.
Purpose
