A vaccine -- Gardasil -- is available to help prevent the spread of some types of HPV. The Centers for Disease Control report that clinical trials in over 11,000 young women have shown the vaccine to be 100% effective for young women in preventing cervical precancers caused by the targeted HPV types, and nearly 100% effective in preventing vulvar and vaginal precancers and genital warts understood to be caused by the targeted HPV types.