Immunogenicity and Safety of V503 in Chinese Males 9 Through 19 Years Old (V503-053)

This study is designed to demonstrate non-inferior immunogenicity of 3 doses of the 9-Valent Human Papillomavirus (9vHPV) vaccine (GARDASIL™9, V503) in Chinese males 9 through 19 years of age, and 2 doses of the 9vHPV vaccine in Chinese males 9 through 14 years of age, compared to the 3 dose regimen in Chinese males 20 through 26 years of age (from Merck Protocol V503-052). The primary hypothesis is that each of the 3-dose regimen in Chinese males aged 9 through 19 years and 2-dose regimens in Chinese males aged 9 through 14 years induces non-inferior competitive Luminex immunoassay (cLIA) geometric mean titers (GMTs) at one month post last dose compared to the 3-dose regimen in Chinese adult males aged 20 through 26 years. A noninferiority margin of 0.67 in the GMT ratio (9 through 19 years of age or 9 through 14 years of age vs 20 through 26 years of age) is used for each HPV type.