(ShareCast News) - Healthcare giant GlaxoSmithKline said its malaria vaccine has passed its last scientific hurdle, although the immunisation programme in sub-Saharan Africa could be still over 12 months away.On Thursday, the treatment, aimed at young children, was given a positive scientific opinion from the European Medicines Agency's Committee for Medicinal Products for Human Use on Thursday.However, the World Health Organisation (WHO), a number of governments in the region and the Vaccines Alliance have yet to approve the rollout of the RTS,S vaccine.Moncef Slaoui, Glaxo's chairman of global vaccines, said the WHO "may introduce certain restrictions or specifications like [to] start in highly endemic areas, or [...] give it in combination with other vaccines given in the same age bracket."It could take several months for the WHO to make a decision, the London-listed group warned, adding that governments across sub-Saharan Africa will then have to determine their individual immunisation policies.The vaccine is the most advanced treatment of its kind, although it only prevents 50% of all cases of malaria in children who are given their first shot when aged between five and 17 months and 25% of cases in those aged between six and 12 weeks when first subject to treatment.The figures are considerably lower than the 80% disease prevention provided by the most common immunisation procedures.The vaccine has been shown to lose effectiveness over a certain period of time, although scientists have hailed the treatment as a "clear benefit" to children in the region."The reality is that the bed net is only effective if you have used it," Slaoui said."With vaccines, once immunized, your protection is with you day and night."My expectation is the effectiveness of this vaccine in real life conditions is going to be substantially higher."Glaxo shares were up 0.04% to 1,357.50p at 08:24 on Friday.