A first-in-man clinical trial to evaluate the safety and immunogenicity of malaria vaccine (JAIVAC-1) in healthy Indian males

Malaria is a serious tropical infectious disease which accounts for a large number of deaths in children under the age of 5 years, especially in sub-Saharan Africa. It is transmitted by the bite of infectious female Anopheline mosquito. There are four species of the protozoan Plasmodia that cause human disease namely, Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae and Plasmodium ovale.
With the emergence of drug resistant strains of Plasmodia and insecticide resistant mosquitoes, there is an urgent need to develop other effective tools that will help in achieving the target of malaria eradication. An effective malaria vaccine is likely to contribute to the repertoire of the available tools to combat malaria. Further, since the majority of deaths caused by malaria are due to the falciparum species, the efforts of the malaria vaccine community have been largely focused on developing a vaccine against Plasmodium falciparum malaria.
Malaria vaccine approaches can be broadly grouped as pre-erythrocytic, blood stage and transmission blocking. There is a strong rationale for developing an erythrocytic vaccine since the blood stage of the malaria parasite is primarily responsible for the clinical symptoms experienced by the host. The underlying principle towards developing an erythrocytic vaccine is that the antibodies generated after administering the vaccine are expected to prevent the merozoites liberated from the liver from invading the red blood cells in circulation. This is expected to prevent lysis of the erythrocytes thereby provide protection against clinical disease.
Most of the earlier efforts in developing a malaria vaccine have been focused on single antigens; this holds true for the blood stage vaccine candidates evaluated. The results of the early development studies with the blood stage candidates have been disappointing and none of these candidates have been able to progress beyond Phase II field trials. It is therefore expected that an effective blood stage malaria vaccine is likely to require the combination of multiple Plasmodium falciparum antigens.
At present, the leading blood stage candidates under development are those which are located either on the merozoite surface or contained within the apical organelles of merozoites. The major erythrocytic vaccine candidates are PfMSP-1, PfMSP-2, PfMSP-3, PfAMA-1, PfEBA-175 and SERA-5. All of these proteins play important functional roles in red cell invasion and multiplication within the erythrocytes of Plasmodium falciparum merozoites.
JAIVAC-1 is a recombinant vaccine composed of two blood-stage P. falciparum antigens. The vaccine was developed by the scientists at International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi. The final vaccine formulation is composed of a physical mixture of two recombinant proteins, namely, PfMSP-119, the 19 kD conserved, C-terminal region of PfMSP-1, and PfF2, the conserved, Duffy-binding- like (DBL) receptor-binding domain of PfEBA-175. JAIVAC-1 is predicted to prevent malaria by targeting these two key parasite proteins that play important functional roles in invasion. This antigen combination is expected to provide an effective strategy to block red cell invasion, reduce blood-stage growth, and prevent malaria.

Study type: Interventional
Enrollment: 45 participants
Allocation: Randomized
Intervention model: Parallel assignment
Trial number: CTRI/2010/091/000301
Phase: Phase I

CTRI registration

Vaccines

Aug 2010 — Mar 2013

India