|The vaccine was administered to children in areas with other interventions against malaria, such as bed nets [EPA]
A new vaccine against malaria will help reduce African children's risk of acquiring the disease by about half, according to the first results of an ongoing phase III trial.
The vaccine, whose trial results were made public on Tuesday, has been developed by the British pharmaceutical giant GlaxoSmithKline's lab in Belgium.
Known as RTS,S the vaccine is the first of its kind to attempt to block a parasite, rather than bacteria or viruses.
Trial results suggested the vaccine reduced the risk of developing clinical malaria by 56 per cent among children aged five to 17 months. They received three doses of the vaccine.
Malaria, spread by mosquitoes, causes high fever and chills and often results in death in sub Saharan Africa and parts of Asia with woefully inadequate medical facilities.
The trial is under way at 11 sites, including Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique and Tanzania. At least 15,460 infants and young children are involved in what GSK described as "the largest malaria vaccine trial to date".
When it came to severe malaria, the stage of the illness that can be fatal and reaches the blood, brain or kidneys, those who received the vaccine showed a 47 per cent lower risk.
"This is remarkable when you consider that there has never been a successful vaccine against a human parasite," said Tsiri Agbenyega, who chairs the RTS,S Clinical Trials Partnership and heads malaria research at Komfo-Anokye Hospital in Kumasi, Ghana.
"While these results are encouraging, we still have a ways to go."
The analysis was done with data from 6,000 children in the trial over a 12-month follow-up after vaccination.
More data is needed from the younger age group - infants aged six weeks to 12 weeks - to better assess how well it works, experts said. Additional results from the younger set are due next year.
The results are published online in the New England Journal of Medicine, and were simultaneously announced at the Malaria Forum hosted by the Bill & Melinda Gates Foundation in Seattle, Washington.
Asked by a reporter whether the Gates Foundation would get behind a vaccine with a success rate of only about half, Regina Rabinovich, director for infectious diseases at the foundation's global health programme, was circumspect.
"This is a key question. The group will ultimately want to understand efficacy, duration and safety," she said.
She said she was "enthusiastic" about the results so far and was awaiting further data.
"Would I prefer to see a 100 per cent effective vaccine? Absolutely."
Trial to continue
The vaccine was administered to children who are in areas with other interventions against malaria, such as bed nets and spraying.
The vaccine was created in 1987 in GlaxoSmithKline Bio's lab in Belgium.
Testing began on healthy adults in Belgium and the US in 1992, before the first Africa study started in Gambia in 1998.
The vaccine works by triggering the immune system to defend itself against Plasmodium falciparum, the deadliest type of malaria parasite.
Several questions remain, including how long the vaccine may last, how well it works in small babies, and how much it will cost, said Seth Berkley, CEO of the Global Alliance for Vaccines and Immunisation (GAVI Alliance).
The trial is set to continue for two more years.