HPV vaccine success in gay and bisexual men Study shows a significant reduction after vaccination of young men. Credit: Jes2ufoto / Getty Images. A significant reduction in four vaccine-preventable human papillomavirus (HPV) strains was seen after a vaccine program that targeted young gay and bisexual men between 16 and 20 years old. The study, called HYPER2 and led by Eric Chow of Monash University along with Alfred Health, saw up to 70% reduction in one type of HPV in gay and bisexual men after the school-based program was introduced in 2013. Australia is the first – and one of only a few – countries to have HPV vaccinations for both boys and girls. There are four different strains of HPV, and symptoms include genital warts and cervical and anal cancer.