This fine and delicate plant is a gift from the sky. The "wormwood" was known in China for more than two millennia for its effectiveness against fevers. Its extract, artemisinin, today is "the only drug which we have to effectively combat malaria", according to Awa Marie Coll-Seck, Executive Director of Roll Back Malaria, after ten years of resistance to chloroquine (nivaquine) and even second generation products there.
Produced in the Chinese provinces of South Africa and some in the European Alps, artemisinin blocks the feverish symptoms, quickly kills the parasite, and "breaks" the epidemic transmission. His great virtue is to have the object of resistance never far. WHO has also prohibited in 2006 to use only: it must be associated with other molecules, as a combination called "ACT", to thwart any adaptation of the parasite. Should indeed be this miracle product to arm's, because there is nothing coming to replace: "Without the artemisinin, it is without for ten years", says François Bompart, Sanofi-Aventis. It therefore passes certain defects. "To be a hell to produce and distribute", explains Philippe Duneton, Unitaid Executive Secretary: the crop cycle is a year and the instability of its combination with other products limits the lifetime of the drug in two years. Not to mention its price: the molecules used in the ACT are 40 times more expensive than chloroquine.
Updated, the old good net wonders. "It is the condom of palu," enthuses Sylvie Chantereau, Executive Director of friends of the Global Fund Europe. "When it is used heavily, its effect is immediate and important: the mortality rate fell by 40.". For 4-5 $, this long-term insecticide-treated nets repels and kills mosquitoes for five years without adverse effects on human and domestic animals.
Already widely distributed in some 15 African countries, it has helped to prevent 350,000 deaths in three years and who plans to provide free 250 million in the next three to five years. "It's a huge market, which currently represents half a billion euros." "Many industrial interest", explained Frédéric Darriet, researcher at the IRD. World production has already doubled between 2004 and 2006, and alongside large groups whose processes are recommended by who, as the Japanese Sumitomo (Olyset Net) or Danish Vestergaard (model PermaNet), small African businesses already placed on the market. Research works on his side during recent years of new fibres and associations of insecticides. But for the moment, it still works to good old pyrethroids, associated with spraying of habitat to the ancient but still effective DDT.
So announced without success for two decades that the anti-malaria vaccine became almost taboo. 50 "Vaccine candidates" are yet running through financing put in place for five years, with the most advanced is the RTS, S developed by researchers at the University of Barcelona, with the financial support of the Bill Gates Foundation and the American laboratory GSK. This vaccine for children and infants is currently in Mozambique, Gabon and Ghana including large scale and advanced test and its placing on the market is expected in 2012.
So far, the problem of these products was their low efficiency: not more than 25 to 30 of reduction in fever clinical access. The acceptable standard for who is a minimum of 30 to 50. "It could yet be an effective vaccine to almost 100 by irradiation, starting from an attenuated parasite, as proposed by the American laboratory Sanaria Inc.. "But it is still too complicated to achieve industrial scale," explains Jean-Louis Perignon, of the Pasteur Institute. The chosen way remains that of genetic engineering, by producing proteins of parasites by bacteria.
But "palu" is mostly a true puzzle. "It's extraordinarily complicated." "At least as against HIV", says one researcher. "There is currently no vaccine against a parasitic disease." "Known not to do," said François Bompart, Sanofi-Aventis.