The latest results, unveiled today , show that the vaccine nearly halves the number of malaria cases in children between five and 17 months old for at least 18 months following the initial shot.
Earlier results, released in March, showed that the effectiveness of the vaccine wanes over time, protecting only 16.8pc of children for as long as four years.
Sir Andrew Witty, chief executive of GSK, said: “While we have seen some decline in vaccine efficacy over time, the sheer number of children affected by malaria means that the number of cases of the disease the vaccine can help prevent is impressive.”
Malaria experts agree that the vaccine has proven itself to be an effective weapon against malaria, but warn that unless it is provided cheaply enough, some low-income countries, dependent on aid from NGOs and charitable foundations, could be prevented from accessing it.
GSK is running its malaria programme as a non-profit operation, but has not yet disclosed how much it will cost to make the vaccine.