Low-cost malaria vaccine proves effective in 5,000 children

Just a year ago, scientists at the University of Oxford presented a malaria vaccine that demonstrated up to 80% protection against the deadly disease in children under 17 months. Now the data are published in the journal ‘The Lancet’ from the phase IIIb clinical trial with nearly 5,000 boys and girls between 5 and 36 months of age, which show that the vaccine -R21/MatrixM- reduced symptomatic cases between 68 and 75% during the following year. According to the authors, the vaccine will be low-cost and could contribute to substantially reducing suffering and deaths from malaria in sub-Saharan Africa. The R21/Matrix-M™ malaria vaccine includes Novavax’s proprietary saponin-based Matrix-M adjuvant and is licensed to the Serum Institute of India. Related News standard No Climate change contributes to the increase in malaria cases in the world María Teresa Benítez de Lugo The anopheles mosquito, which transmits the parasite that causes malaria in humans, modifies its behavior in the face of extreme weather events such as waves heat or flooding «The study demonstrates the usefulness of a second malaria vaccine developed in Oxford, with a formulation very similar to the first vaccine that the WHO recommended after another larger multicenter phase 3 trial and a series of pilot studies of implementation in three African countries (RTS,S/AS01E or Mosquirix from GSK),” Carlota Dobaño, head of the Malaria Immunology Group at the Barcelona Institute for Global Health (ISGlobal), told Science Media Center. She adds that both constants of an antigen against the malaria parasite based on the circumsporozoite protein, from the surface of Plasmodium falciparum injected by the transmitting mosquito, fused to the surface antigen of the hepatitis B virus and formulated with an adjuvant that stimulates. an inflammatory response by the innate immune system, and induce high levels of antibodies against the parasite. The vaccine shows high efficacy in areas of seasonal malaria when administered just before the rainy months associated with high transmission of the infection, and less efficacy in places of less intense and perennial transmission. The authors indicate that a high number of vaccine doses can be produced economically, which will benefit a greater number of African children from receiving it, given the current limitation to the level of manufacturing of the other available vaccine. Dobaño points out to others that “both vaccines are considered first generation, with efficiencies that can be improved, and knowledge gaps need to continue to be investigated (for example, why they do not protect 90-100% of children) to be able to optimize them in second generations.” ». Health system The main challenge facing the malaria vaccine is the integration of vaccination into the health system, as an intervention in the strategy for the control and elimination of malaria. Thus, it should be able to be integrated into the vaccination schedule that is already in operation, acknowledges Consuelo Giménez Pardo, from the Parasitology Area of ​​the University of Alcalá (UAH). “But in malaria vaccines, there are no panaceas,” the also director of the Master’s Degree in Humanitarian Health Action (UAH-Médicos del Mundo) clarifies to SMC. «It must be taken into account that in subunit vaccines the demonstrated efficacy is reduced and is limited to the range between 5 and 7 months of age, for adults these figures decrease to 34% efficacy, in addition to that, according to the evidence available, it does not seem that the protection lasts over time, so vaccinated children would be exposed to malaria again from a very young age. In general terms, he concludes, efforts should be aimed at “improving capabilities, both in human resources and infrastructure, to efficiently monitor and manage resistance to insecticides, as well as to have new products (insecticides, treatments and vaccines). ). ) adequate and accessible, useful in malaria control.