Scientists with the Walter Reed Army Institute of Research (WRAIR) recently conducted a human challenge model that tested a vaccine candidate for Plasmodium vivax malaria.
Malaria continues to afflict countless people in developing nations around the world. P. vivax malaria is particularly challenging because it can be present without any symptoms, remaining dormant for years. Weeks or even months after contracting the infections, patients can develop active symptoms.
The new vaccine has been jointly developed and tested by WRAIR and GlaxoSmithKline. In the study, 30 volunteers received three vaccine doses. It was found to be efficient or at least cause a delay in malaria onset when the researchers evaluated the blood smears of the volunteers.
"Findings from the analysis of the immune response of vaccinated subjects have given us clues to improve vaccine candidates and studies are now underway at WRAIR to develop next generation vivax vaccines," Col. Robert Paris, director of the U.S. Military Malaria Research Program at WRAIR, said. "Vaccines and antimalarial drugs are both critical needs for the [Department of Defense] to protect service members from malaria."
The vaccine is designed to prevent infection from P. vivax. This would decrease the mortality and sickness caused by vivax malaria, which is a common source for malaria infections. It is especially common in service members who are deployed.
"This study represents the first vaccine study to test the effectiveness of a P. vivax vaccine candidate in humans using controlled human malaria infection," Lt. Col. Jason W. Bennett, the study's lead investigator, said.