Cairns ME, Sagara I, Zongo I, et al. - Given that a high malaria burden, despite introduction of seasonal malaria chemoprevention (SMC) for children under 5 years of age, has been reported in several countries including Burkina Faso and Mali which are amongst the most important contributors to the global burden of malaria cases and deaths, researchers sought to ascertain if SMC retains a high level of protection in these areas and how improvement in its impact could be attained. They used data from a large but closely supervised clinical trial in 2 districts in southern Burkina Faso and Mali to determine the level of protection provided by SMC. Over 3 years, SMC was delivered 4 times per year, outreaching a very high percentage of children. In specific substudies, rare occurrence of molecular markers of resistance to the combination of antimalarials used for SMC was noted amongst malaria parasites and the SMC combination was reported as highly effective in curing infections detected at the end of the rainy season. The period immediately after each SMC course had marked reduction in malaria incidence. In the first 4 weeks after SMC, they observed reduction in malaria cases by 78%, and malaria hospitalizations and deaths from malaria by 87%. Despite the benefits of SMC, the study areas had very high number of malaria cases, hospital admissions for malaria, and deaths from malaria. A large peak was reported in July each year, coinciding with the initiation of the rainy season, prior to the beginning of SMC delivery in August. Results here highlight the necessity for continuing support of SMC programmes. They suggest the necessity for providing a fifth monthly SMC course to sufficiently cover the whole transmission season in the study areas and in settings with similar epidemiology.