Clinical research on malaria: what for the future?

Malaria still remains one of the main public health problems in the world. In spite of early and numerous clinical trials, the situation seems to have been worsening in the last ten years. Malaria clinical research involves several levels: - on the human host, the main interventions are therapeutic management of clinical cases and prevention of the disease by chemoprophylaxis or vaccination; - on the vector which transmits parasites, mass use of insecticides seems to be the most adequate way of control. Several meta-analyses have been performed on this topic (in particular, the Cochrane Database Library has published studies on malaria prevention during pregnancy, management of clinical malaria attacks, vaccine trials or impregnated bed net trials). All these studies show the uneven quality of trials (only 10% to 50% can be kept in the analysis for methodological reasons), which seldom lead to similar conclusions. Besides, as resistances of both parasites and vectors to drugs or insecticides are regularly increasing, trials have to be repeated and new molecules have to be found and evaluated. Finally, practical application of such interventions may be difficult, due to the heterogeneity of epidemiological situations and the poverty of target populations. Various initiatives aiming to develop malaria clinical research have recently been launched. Donators are public or international (Global Fund, Roll Back Malaria Initiative, NIH, EDCTP programme), as well as private (Bill & Melinda Gates Foundation). These substantial funds should enhance the research of new antimalarial drugs and large-scale, adequately designed trials. However, to make sure these trials really benefit to populations exposed to the disease, ethical principles should be coelaborated with developing countries, within collaborative networks between laboratories from industrialized and developing countries.