No long-term evidence of hyporesponsiveness after use of pneumococcal conjugate vaccine in children previously immunized with pneumococcal polysaccharide vaccine by Licciardi, P, Toh, Z, Clutterbuck, E, Balloch, A, Marimla, R, Tikkanen, L, Lamb, K, Bright, K, Rabuatoka, U, Tikoduadua, L, Boelsen, L, Dunne, E, Satzke, C, Cheung, Y, Pollard, A, Russell, F, Mulholland, E