The objective of this study is to evaluate the immune memory through the administration of an additional dose of GSK Biologicals' pneumococcal conjugate vaccine GSK1024850A, the antibody persistence and long-term effect on nasopharyngeal carriage of S. pneumoniae and H. influenzae in subjects primed and boosted with GSK Biologicals' pneumococcal conjugate vaccine GSK1024850A in previous primary and booster studies. For subjects that did not receive the investigational vaccine during the primary and booster study, the objective is to evaluate immunogenicity, safety and reactogenicity of a 2-dose catch-up vaccination with GSK Biologicals' pneumococcal conjugate vaccine GSK1024850A.