Malaria is one of the world’s leading killers, claiming the lives of over 250,000 children in Africa every year. Researchers have been trying for decades to come up with a viable solution to this global health problem, but haven’t made much progress. That is, until recently. This week, the world’s first malaria vaccine has begun a wide rollout, commencing in Malawi before being introduced into Ghana and Kenya over the following weeks. The RTS/S vaccine, currently the most advanced malaria vaccine in development, works by training the immune system to attack the malaria parasite, which is spread by mosquitos. The vaccine has been shown to prevent nearly 40 percent of malaria cases. While this isn’t an extraordinarily efficacious rate for a vaccine, it could still save thousands of lives in affected African areas. This initial pilot program is estimated to run until 2024, after which the results will be evaluated and broader implementation in other countries will be considered.