Malaria vaccine trial. A Tanzanian baby is injected with an experimental malaria vaccine while being breast-fed. This is the first African field trial of the new vaccine (SPf66). Malaria remains prevalent in the tropics despite the World Health Organisation's attempts to eradicate the disease. One reason for this is the emergence of drug-resistant strains of the malarial parasite (Plasmodium sp.). Discovery of an effective vaccine would make prevention a realistic possibility and might save the one million African children who die from the disease each year.