Over 1 million people a year die from malaria, and many are young children. Health officials fear that the disease will begin spreading much more rapidly, because it has developed resistance to drugs that formerly were effective -- as well as cheap enough to make widespread distribution possible.

Population growth in tropical regions adds to the number of individuals who may be at risk of contracting malaria. Half the world's population, or approximately 3.5 billion people, could be living in areas where malaria is transmitted within the next ten years, the article suggests.

The malaria vaccine RTS,S/AS02A has shown promise as a potential vaccine against Plasmodium falciparum malaria (the most severe form of the disease). It acts at the "pre-erythrocytic stage" -- that is, before the red blood cells become infected.

The phase II trial was conducted among children aged 1-4 years in Mozambique. Pedro L. Alonso of the Hospital Clinic, University of Barcelona, Spain, and Manhi