On October 16, 2009, the Food and Drug Administration licensed quadrivalent human papillomavirus vaccine (HPV4; Gardasil, Merck & Co. Inc.) for use in males aged 9 through 26 years for prevention of genital warts caused by human papillomavirus (HPV) types 6 and 11. HPV4 had been licensed previously for use in females aged 9 through 26 years for prevention of HPV 6, 11, 16, and 18-related outcom...

The quadrivalent HPV types 6, 11, 16, 18 vaccine (Gardasil®) is a recombinant vaccine comprising purified virus-like particles derived from the L1 capsid proteins of HPV types 6, 11, 16 and 18. The vaccine was highly immunogenic. Geometric mean titres (GMTs) and seroconversion rates for all four HPV types at month 7 in males aged 10-15 years were noninferior to those in females aged 16-23 years...