Study shows progress in malaria vaccine trial in Africa

Scientists across Africa on Friday announced progress in their research for a vaccine against malaria, giving hope to defeating the continent’s biggest killer.Scientists in Kenya and in South Africa said a 12-month round of trials in several African countries has showed good efficacy levels among infants who are the most victims of the disease in Sub-Sahara Africa. “We have made significant progress in recent years in our battle against malaria, but the disease still kills 655,000 people a year - mainly children under five in sub-Saharan Africa. An effective malaria vaccine would be a welcome addition to our tool kit,” Dr. Salim Abdulla, a principal investigator for the trial from the Ifakara Health Institute, Tanzania told journalists in Nairobi.The new vaccine trial has been given the code name RTS.S. “This study indicates that RTS.S can help to protect young babies against malaria. Importantly, we observed that it provided this protection in addition to the widespread use of bed nets by the trial participants,” said Abdulla. The project to research on effective malaria vaccine started in 2001, when Malaria Vaccine Initiative (MVI), a body funded by Bill & Melinda Gates Foundation entered into partnership with GSK to study the vaccine candidate’s ability to protect young children in Sub-Saharan Africa.Over time, the partnership expanded to include the 11 African research centres and, in some instances, associated scientific institutions from Europe and the United States. MVI has invested 200 million dollars while GSK has invested more than 300 million dollars to date and expects to invest more than 200 million dollars before the completion of the project. The first complete set of results in children aged 5 to 17 months and combined data for severe malaria in the first 250 cases from those aged 6 weeks to 17 months were published in the New England Journal of Medicine in November 2011.On Friday, results from the large-scale Phase III trial, published online in the New England Journal of Medicine, show that the RTS.S malaria vaccine candidate can help protect African infants against malaria.”When compared to immunization with a control vaccine, infants aged 6-12 weeks at first vaccination, those vaccinated with RTS.S had one-third fewer episodes of both clinical and severe malaria and had similar reactions to the injection. In this trial, RTS.S demonstrated an acceptable safety and tolerability profile,” said a statement released by the scientists.Eleven African research centres in seven African countries are conducting this trial, together with GlaxoSmithKline (GSK) and the PATH Malaria Vaccine Initiative (MVI), with grant funding from the Bill & Melinda Gates Foundation to MVI. Abdulla said although the efficacy level of the just concluded trials is lower than what was realized last year with the older 5- 17 month age category children. “It makes us even more eager to gather and analyze more data from the trial to determine what factors might influence efficacy against malaria and to better understand the potential of RTS.S in our battle against this devastating disease,” Abdulla said. “We were also glad to see that the study indicated that RTS.S could be administered to young infants along with standard childhood vaccines and that side effects were similar to what we would see with those vaccines,” he said.Some of the scientists in the team said the lower efficacy could be because the immune systems of the children of 3-4 months is still developing.They reported that there was no increase in overall reporting of serious adverse events between the infants vaccinated with the RTS.S malaria vaccine candidate and infants in the control group, which received a comparator vaccine. “While the efficacy seen is lower than last year, we believe these results confirm that RTS.S can help provide African babies and young children with meaningful protection against malaria,” said Sir Andrew Witty, CEO, GSK.”They take us another important step forward on the journey towards having a new intervention available against this disease, which is a huge burden on the health and economic growth of Africa. “The scientists said follow-up in this Phase III trial will continue to provide more data for analyses to better understand the different findings between the age categories. These data and analyses should also provide insights into the vaccine candidate’s efficacy in different malaria parasite transmission settings. More data on the longer-term efficacy of the vaccine during 30 months of follow-up after the third dose, and the impact of a booster dose are expected to be publicly available at the end of 2014.