There’s a three month trial period jual viagra online There were, according to the World Health Organisation (WHO), about 200m cases of malaria around the world in 2010, with 660,000 deaths, 90% of which were in Africa, mostly of young children. The prospect of a vaccine is therefore exciting to patients and health experts alike. But developing one is difficult. Malarial parasites, though small and single-celled, are much more complex than the bacteria and viruses that are the usual targets of vaccines. To date there has been no successful vaccine against such a complex organism. Work on RTS,S has been going on for decades.