An experimental malaria vaccine helps protect children for as long as 18 months against the deadly parasite, researchers report. The company that makes the vaccine, GlaxoSmithKline, says it will move ahead to develop the vaccine commercially.
It's not a home run by any stretch. The vaccine, called RTS,S, cut the number of cases in half after 18 months. Most childhood vaccines provide at least 90 percent protection. And it only reduced the number of cases in infants by a quarter.
But in the world of malaria vaccines, it's good enough. Researchers have worked for decades to try to make a vaccine against the malaria parasite, which is carried by mosquitoes. It has been especially difficult.
Malaria kills 660,000 people a year, mainly babies in the poorest parts of sub-Saharan Africa, and scientists say an effective vaccine is key to attempts to eradicate it.
"Many millions of malaria cases fill the wards of our hospitals. Progress is being made with bed nets and other measures, but we need more tools to battle this terrible disease," said Halidou Tinto, a lead investigator on the RTS,S trial from Burkina Faso.
Tuesday's latest readout from the malaria trial, which is Africa's largest ever clinical trial involving almost 15,500 children in seven countries, were presented at a medical meeting in Durban, South Africa.
GSK is developing RTS,S with the non-profit PATH Malaria Vaccine Initiative (MVI), with grant funding from the Bill & Melinda Gates Foundation to MVI.
Earlier studies on the vaccine suggested it was 65 percent effective in babies analyzed six months after vaccination, and only around 50 percent in five to 17 month-olds.
And further data released earlier this year found RTS,S's effectiveness wanes over time, with the shot protecting only 16.8 percent of children over four years.
Despite these drawbacks, David Kaslow, vice president of product development at PATH, said RTS,S would serve as a useful additional tool alongside other malaria control measures such as mosquito nets, insecticides and anti-malaria drugs.
"Given the huge disease burden of malaria among African children, we cannot ignore what these latest results tell us about the potential for RTS,S to have a measurable and significant impact on the health of millions of young children in Africa," he said in a statement.
"This trial continues to show that a malaria vaccine could potentially bring an important additional benefit beyond that provided by the tools already in use."