A clinical trial has revealed the potential of the RH5.1/Matrix-MTM malaria vaccine candidate to provide effective protection against blood-stage malaria, marking a major milestone in the fight against the disease.
The results of a phase 2b clinical trial, published in The Lancet Infectious Diseases, demonstrate that the vaccine is both well-tolerated and effective, particularly in children aged 5 to 17 months in Nanoro, Burkina Faso.
The double-blind, randomized, controlled trial enrolled over 360 children aged 5 to 17 months. Participants were divided into two groups: one received the RH5.1/Matrix-MTM vaccine, while the other received a rabies vaccine as a control.
The vaccine group achieved significant results, with those on a 0, 1, and 5-month dosing schedule achieving 55% protection against clinical malaria over a six-month period. Additionally, the vaccine demonstrated over 80% efficacy in reducing high levels of parasites, indicating its potential to prevent severe cases of the disease.
Malaria, caused by Plasmodium falciparum, remains a leading cause of death among children under five in Africa. Blood-stage malaria, when the parasite infects red blood cells, is associated with severe symptoms, including fever, chills, anemia, and organ failure.
Professor Angela Minassian of the University of Oxford, who leads the blood-stage malaria vaccine program, highlighted the significance of the findings. “Our goal is to significantly reduce severe cases and deaths by targeting the blood-stage of the disease. Adding RH5.1/Matrix-MTM to existing liver-stage vaccines could provide a vital second line of defense,” she said.
Professor Halidou Tinto, Regional Director at the Institut de Recherche en Sciences de la Santé (IRSS), emphasized the broader impact on children’s health. “Frequent malaria infections impair growth and development. This vaccine offers hope for healthier childhoods and better outcomes.”
Professor Simon Draper, inventor of the RH5.1 vaccine, described the trial as a “major milestone” in the quest to develop a second-generation malaria vaccine. The study has opened the door for combining this vaccine with liver-stage vaccines to achieve even higher efficacy.
The trial was funded by global health organizations, including the European and Developing Countries Clinical Trials Partnership and the Wellcome Trust. This landmark research underscores the potential for new, combined strategies to combat malaria and improve health outcomes in endemic regions.