Over 250 Institutions participate in the effort of sharing data on the efficacy of antimalarial drugs, which involves standardising and re-analysing data. Professor Philippe Guérin is Director of the WorldWide Antimalarial Resistance Network (WWARN). The best lines of defence against malaria are avoidance of mosquito bites and effective drug therapy. WWARN tracks the emergence of antimalarial drug resistance to ensure that anyone affected by malaria receives effective and safe drug treatment.