Fig. 1

Study design. Randomization, the primary vaccination phase, the initial antibody persistence phase (Years 1–5), the current long-term persistence phase (Years 7–10)*, and the booster dosing phase are shown. MenACWY meningococcal A, C, W, Y, PS polysaccharide, TT tetanus toxoid
*Study visits for Year 6 of the persistence phase were not conducted due to delay in study approval