Brian Greenwood (London School of Hygiene and Tropical Medicine, UK) and colleagues state that prevention and treatment of malaria could be greatly improved with existing methods if increased financial and labour resources were available. Combination therapies based on drugs derived from the plant Artemisia annua (ACTs) have now been adopted by many endemic countries, although cost is likely to be a problem in ensuring their widespread use. ACTs are highly effective, even in areas where there is a high level of resistance to other antimalarial drugs. (See this week's issue Lancet 365; 1467-73, Lancet 365; 1474-1480) Insecticide-treated bed-nets provide a simple but effective means of preventing malaria, especially with the development of longlasting nets in which insecticide is incorporated into net fibres and is not removed during washing.
However, the authors state that new approaches to prevention and treatment are needed including malaria vaccines. One malaria vaccine, RTS, S/AS02 has provided substantial, short-lived protection in volunteers exposed experimentally to bites by infected mosquitoes and in semi-immune adults in The Gambia exposed to natural infection. (See Lancet 2001; 358: 1927-34) In a subsequent trial in Mozambican children, the RTS, S/AS02 vaccine gave 30% protection against the first clinical episode of malaria and 58% protection against severe malaria. (See Lancet 2004; 364: 1411-20) Other promising candidates are undergoing clinical trials.
Professor Greenwood states: "Malaria vaccine research has progressed rapidly over the past few years, helped by the availability more funds and by improved organisation mediated through organisations such as the Malaria Vaccine Initiative. However,
Contact: Joe Santangelo