HPV types 16 and 18 are responsible for 70 percent of cervical cancers and types 6 and 11 for 90 percent of sexually transmitted genital warts (wart). Cervical cancer is one of the most common cancers (cancer) in women worldwide, with about 500,000 new cases and more than 200,000 deaths occurring each year. The vaccine has the greatest effect when given to 11- and 12-year-old girls as a series of three injections over a period of six months. In clinical trials the vaccine was almost 100 percent effective in preventing precancerous cervical lesions. In addition, there is some evidence that Gardasil may be effective in preventing genital warts and cancers of the penis and anus in males.