TRAP-HPV stands for Transmission Reduction And Prevention with HPV vaccination. HPV (human papillomavirus) is the leading cause of cervical cancer, the second most common cancer in women. Prophylactic vaccines against certain high-risk HPV types have been shown to be effective in preventing infection. However, much remains to be understood on the effects of HPV vaccine on the blockage of transmission of target HPV types to sexual partners of vaccinated individuals. TRAP-HPV is a clinical trial aimed to determine the efficacy of an HPV vaccine in reducing transmission of genital, anal, and oral HPV infection in sexual partners of vaccinated individuals.