New Japanese Vaccine Cuts Malaria Risk by 70 Pct

Osaka, May 30 (Jiji Press)--A team of researchers led by a Japanese professor has developed a vaccine that cuts the risk of malaria in humans by some 70 pct, according to a recent article published on the U.S. journal PLOS One. If the vaccine is put to practical use, the number of deaths caused by the mosquito-borne disease is expected to decrease markedly. At present, no antimalarial vaccine is commercially available. Malaria is caused by parasites borne by Anopheles mosquitoes. Of the four malaria-causing parasites that have been identified, Plasmodium falciparum is most deadly. According to World Health Organization data, some 660,000 people, mainly infants, die of the disease around the world every year. There are medicines to prevent the disease and treat patients. But parasite resistance to antimalarial drugs is increasingly becoming a problem. The vaccine developed by the team, led by Toshihiro Horii, professor at Osaka University's Research Institute for Microbial Diseases, is called BK-SE36. The dry powder vaccine is injected after being dissolved in water. In Japan, its safety was confirmed in a clinical trial in 2005. A trial carried out in Uganda between 2010 and 2011 found no abnormalities, such as unusual immune reactions, in subjects. In a follow-up survey of 132 subjects in Uganda, aged between six and 20, the team compared subjects who did not receive any BK-SE36 injections with those vaccinated twice. Of those without any injection, 21 were infected with malaria within one year, while the number was smaller at seven in the vaccinated group. Taking some other factors into consideration, the vaccine lowered malaria risk by 72 pct, the team said. The vaccine far outperformed the 31 pct risk decline achieved by a different new vaccine developed by a British company and is now going through a clinical trial. "We want to put (our vaccine) to practical use in five years after conducting a clinical trial on infants between zero and five, who account for the bulk of malaria deaths," Horii said. END