A malaria vaccine has proved to be 77% effective in early trials and could be a major breakthrough against the disease, say its developers from the University of Oxford.
Malaria kills more than 400,000 people a year, mostly children in sub-Saharan Africa.
But despite many vaccines being trialled over the years, none has met the required target for success.
The researchers say the vaccine could have a major public health impact.
When trialled in 450 children in Burkina Faso, the vaccine was found to be safe, and showed "high-level efficacy" over 12 months of follow-up.
Larger trials in nearly 5,000 children between the ages of five months and three years will now be carried out across four African countries, to confirm the findings.