Safety and Immunogenicity of Extended 2-dose Regimens of 9-valent Human Papillomavirus (9vHPV) Vaccine (V503-069)

This is a 96-month safety and immunogenicity study conducted in boys and girls 9 to 14 years of age and in young women 16 to 26 years of age. From this study, the goal is to establish that the investigational extended 2-dose regimens (0, 12 months; 0, 24 months; 0, 36 months; and 0, 60 months) studied in boys and girls 9 to 14 years of age are generally safe and immunogenic, with an antibody response that is not inferior to that observed in young women 16 to 26 years of age who receive the standard 3-dose regimen of 9-valent human papillomavirus (9vHPV) vaccine at 0, 2, and 6 months (i.e., the population and dose regimen used to establish 9vHPV vaccine efficacy).