Participant progression through the study. ACWY-TT = group of participants who received one dose of MenACWY-TT at Month 0. Men-PS = group of participants who received one dose of the MenACWY polysaccharide vaccine at Month 0. ATP = according to protocol. TVC = total vaccinated cohort. N = number of participants. The numbers of participants withdrawn are given between the TVC vaccination stage and the total cohort for each timepoint during the persistence phase (Year 1, Year 2, and Year 3).