The world may soon have another powerful weapon against malaria, which kills half a million people each year. Data from a trial involving 4800 children in four African countries suggest a vaccine developed at the University of Oxford, R21/MatrixM, provides significant protection. If endorsed by the World Health Organization, it would become the second WHO-approved vaccine against malaria. The first, called RTS,S or Mosquirix, has been given to 1.8 million children in Ghana, Malawi, and Kenya, but the 18 million doses expected to be available between now and 2025 are only 10% of what is needed to protect the estimated 40 million children born every year in malaria-affected areas. The developers of R21 have already worked with the Serum Institute of India (SII), one of the world’s biggest vaccine makers, which says it can produce more than 100 million doses per year. And at an estimated price of less than $5 per dose, the new vaccine may be less expensive than RTS,S, if approved by WHO.