Healthy, meningococcal-vaccine naïve toddlers aged 12 to 23 months are randomized either to a single dose of MenACYW conjugate vaccine alone or in combination with other pediatric vaccines in healthy toddlers in South Korea (measles-mumps-rubella vaccine [MMR] + varicella vaccine), the Russian Federation (pneumococcal conjugate vaccine [PCV13]), and Mexico (diphtheria, tetanus, acellular pertussis, hepatitis B, poliomyelitis, and Haemophilus influenza type-b conjugate vaccine [DTaP-IPV-HB-Hib]). Immunogenicity (pre- and 30 days post-vaccination) and safety are assessed.