Two studies have noted that based on results from Phase II trials in Africa that the new malaria vaccine is effective in preventing both infection and the mosquito-borne disease itself in infants and children and cut illnesses by more than half in field trials. The vaccine, called RTS, S, is scheduled to begin a third and final phase of clinical trials early next year, could become the first to protect children from malaria. If all goes well the vaccine could be ready for licensure in 2011 and available for use by 2012 said experts.

Dr. Christian Loucq, director of the PATH Malaria Vaccine Initiative said, "Malaria is killing almost 1 million people, mostly African children, every year. Clearly, the world needs a safe and effective malaria vaccine." He added that although there are several other vaccines being developed for malaria, RTS. S is furtherest along in its testing process and would therefore be the first.

"These studies offer further evidence that RTS, S provides both infants and young children with substantial protection against the disease," Loucq said. "We are closer than ever before to having a malaria vaccine for use by the children in Africa."

The vaccine has been developed by drug maker Glaxo-Smith-Kline, with support from the PATH Malaria Vaccine Initiative, a global nonprofit consortium that works with pharmaceutical companies. Dr. W. Ripley Ballou, deputy director for vaccines and infectious diseases for the Bill and Melinda Gates Foundation, which helped fund the research said if Phase III trials are a success then it would be "an extraordinary scientific triumph. But more importantly," Ballou added, "it could save millions of children's lives."

In one study, 340 Tanzanian infants under 1 year old received the RTS, S/ASO2 vaccine along with other vaccines for diphtheria, tetanus, pertussis and heamophilus influenzae B. Lead researcher Dr. Salim Abdulla, head of the Bagamoyo Research and Training Centre of the Ifakara Health Institute, in Tanzania said, "There was a 65 percent reduction in first infection from malaria in those infants who received three doses of the vaccine and were followed over a six-month period. A safe and efficacious malaria vaccine for children in Africa may be available in the near future and have the potential of alleviating a huge burden of malaria disease," he added.

In the second study, 894 children in Kenya and Tanzania, ages 5 to 17 months, were given either three doses of the malaria vaccine or a rabies vaccine and researchers found a 53 % reduction in the risk of developing malaria among children who received the RTS, S vaccine. Lead researcher Philip Bejon, of the Kenya Medical Research Institute (KEMRI)-Wellcome Collaborative Research Programme and the Centre for Tropical Medicine at the University of Oxford, in England said, "If these findings were replicated in a Phase III multi-center study, we would expect that study to lead to an application for a license for RTS, S/AS01 as a vaccine to prevent clinical malaria. The vaccine would be only partially effective, but may still be a useful addition to malaria control programs," Bejon added.

Joe Cohen, vice president for vaccines for emerging diseases at GlaxoSmithKline, who has worked on RTS, S since its inception 22 years ago said developing a malaria vaccine has proven a challenge because the parasite is adept at evading the immune system, and many people in Africa live in areas where they are constantly re-infected.

The findings were published online Dec. 8 in the New England Journal of Medicine.