Persistence of the immune response at 5 years of age following infant immunisation with investigational quadrivalent MenACWY conjugate vaccine formulations. - Khatami, A; Snape, MD; Davis, E; Layton, H; John, T; Yu, L; Dull, P; Gill, C; Odrjlin, T; Dobson, S; Halperin, SA; Langley, J; et al. (Vaccine, 2012)