An Independent Ethics Committee approval of the protocol was obtained before enrolment; and written, informed consent was obtained from each subject or, if applicable (subjects this website under 18 years of age), the subject’s parents or legal guardians. Study site monitoring was performed by Quintiles (Bogota,

Colombia). Healthy persons 11–18 years of age who were appropriately vaccinated against diphtheria (D), T, and pertussis (P) (i.e., had received five doses of paediatric DTP/DTaP before their seventh birthday; if the fourth dose was administered on or after their fourth birthday, the fifth dose was not required) with no prior history of sexual activity and no intention VE-821 order of becoming sexually active during the study period, were eligible for inclusion in the study. Subjects were excluded if they had ever received meningococcal or HPV vaccine; had been vaccinated with any licensed vaccines within 1 month of enrolment; had received any investigational agents or vaccines in the 3 months before enrolment; had any serious acute, chronic, or progressive disease; or had a known or suspected impairment/alteration of immune function. A total of 1620 subjects were randomized 1:1:1 to three groups stratified by gender and age (11–14 years of age and 15–18 years of age) to receive: • Group 1 (n = 540)

MenACWY-CRM concomitantly with Tdap (Boostrix™, GlaxoSmithKline, Rixensart, Belgium) and HPV (Gardasil™, Merck & Co., NJ, USA), followed by HPV at 2 and 6 months (MenACWY-CRM + Tdap + HPV). All subjects received a single dose (0.5 ml) of each vaccine, administered intramuscularly in the right deltoid area (MenACWY-CRM), the left deltoid area (Tdap), and the upper anterolateral

area of the thigh (HPV). Each subject was observed of for 30 min post-vaccination for local or systemic reactions, or anaphylaxis. Oral temperature was recorded, and the subject, or the parents or legal guardians, where applicable, were given diary cards to record any local (pain, erythema, and induration) or systemic (chills, nausea, malaise, myalgia, arthralgia, headache, and rash) reactions that occurred between Day 1 and Day 7. Any adverse events (AEs) requiring medical attention were recorded for 1 month post-vaccination, and any medically significant and serious AEs (SAEs) were recorded for 6 months post-vaccination. Blood samples (20 ml) were obtained at the first visit, before vaccination, and 1 month post-vaccination with MenACWY-CRM and/or Tdap, and 1 month following the final dose of HPV. Immunogenicity of the MenACWY-CRM vaccine was evaluated by serum bactericidal assay using human complement (hSBA) to Neisseria meningitidis serogroups A, C, W-135, and Y.