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HPV Vaccine Works for Boys: Study Shows First Clear Benefits

By Kristen Bole, UCSF News Office | February 4, 2011

The vaccine for human papillomavirus (HPV) can prevent 90 percent of genital warts in men when offered before exposure to the four HPV strains covered by the vaccine, according to a new multi-center study led by H. Lee Moffitt Cancer Center and UCSF.

The four-year, international clinical trial, which also found a nearly 66 percent effectiveness in the general population of young men regardless of prior exposure to these strains, provides the first reported results of using the HPV vaccine as a prophylactic in men.

Initial data from this study informed the Food and Drug Administration's decision to approve the vaccine for boys in 2009 to prevent warts, while results from a substudy led the FDA to expand approval late last year to prevent anal cancer. Findings can be found in the Feb. 3 issue of the New England Journal of Medicine, or online at www.nejm.org.

While the HPV vaccine was approved in 2006 for girls to prevent cervical cancer, the vaccine's benefit for young men was not initially addressed. Yet infection and diseases caused by HPV are common in men, the researchers said, including genital warts, which are one of the leading sexually transmitted diseases (STD) for which treatment is sought nationwide. The Centers for Disease Control and Prevention estimate that half of all sexually active Americans will get HPV at some point in their lives.

"This is an exciting development in the STD world," said Joel Palefsky, MD, a UCSF professor of medicine who co-led the research along with epidemiologist Anna R. Giuliano, PhD, from the H. Lee Moffitt Cancer Center and Research Institute, in Tampa, FL. "It shows that if we vaccinate males early enough, we should be able to prevent most cases of external genital warts in this population."

While warts are often considered an annoyance, rather than a life-threatening disease such as cervical cancer, Palefsky noted that warts are a common problem in young people and are often associated with depression, social stigma and loss of self-esteem. Complications of wart treatments are also quite common, he said.

The double-blind study included 4,065 healthy men aged 16-26 years, spanning 71 sites in 18 countries. Of those patients, 85 percent reported having exclusively female sexual partners, with the remainder self-identified as having sex with men.


Read more at Kristen Bole, UCSF News Office