A vaccine that can protect children from life-threatening malaria is still effective after 18 months, say researchers.
Researchers already knew the vaccine offered six months of protection. The extended period of security has raised hopes for a vaccine that prevents deaths from malaria.
The results were announced yesterday (15 November) at an international malaria conference in Cameroon and published online by The Lancet.
The vaccine reduced the number of all mild cases of malaria by 35 per cent and halved the number of serious infections.
Melinda Moree of the Malaria Vaccine Initiative told BBC Online that the vaccine lasts long enough to make it "a real public health intervention that can have an impact on malaria in Africa".
The vaccine, which is being developed by GlaxoSmithKline, will need years of testing before it can be made available.