The world's first malaria vaccine could be on the market as early as 2015, GlaxoSmithKline said after its advanced clinical trials proved encouraging.The FTSE 100 company's large-scale Phase III clinical trial showed its experimental malaria vaccine candidate helped reduce cases of the disease in children for up to 18 months after vaccination. The trial found the number of malaria cases in young children aged 5-17 was halved by the jab, which is currently called 'RTS,S'.Chief Executive Officer Sir Andrew Witty said the data support GSK's decision to submit a regulatory application for the vaccine candidate.In a statement released at one minute after midnight on Monday night, the group said it intended to submit a regulatory application to the European Medicines Agency (EMA) in 2014.Glaxo added that the World Health Organization (WHO) had suggested a policy recommendation for the vaccine candidate was possible as early as 2015 if it is granted a positive scientific opinion by EMA.Witty 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."The vaccine's efficacy was assessed separately at each of the 11 trial sites in seven African countries, which represented a wide range of malaria transmission settings, and was found to be statistically significant at all sites in young children and at four sites in infants.Shares in GSK were down 0.3% to 1,561.42p at 09:31 on Tuesday.OH