WEDNESDAY, Sept. 9, 2009 (HealthDay News) -- U.S. drug advisors recommended Wednesday that use of the vaccine Gardasil, already administered to help prevent cervical cancer in women, be expanded to help prevent genital warts in young males.
A U.S. Food and Drug Administration advisory panel voted to recommend the expanded use of the vaccine for males 9 to 26. The FDA is not required to follow its advisory panels' recommendations, but it typically does.
The vaccine targets the human papilloma virus, which can cause genital warts in both males and females, cervical cancer in women and also penile and anal cancer in men -- although these remain much rarer than cervical malignancies.
The vaccine is manufactured by drug maker Merck & Co.
Merck had asked the FDA to approve Gardasil for males ages 9 to 26. It is already approved in females 9 and older to help prevent cervical cancer.
Before the Gardasil vote, the committee on Wednesday also voted that a second HPV vaccine, GlaxoSmithKline's Cervarix, seems safe for girls and women ages 10 to 25 for the prevention of cervical cancer. Studies have shown that the vaccine prevents infection with HPV 93 percent of the time. The introduction of Cervarix was delayed in 2007 when the FDA said it needed more research on the vaccine.
The FDA advisors -- comprising the Vaccines and Related Biological Products Advisory Committee -- said Wednesday that newer studies suggest the Cervarix vaccine is safe, but they recommended follow-up studies to look for miscarriages and muscular problems reported by a small number of patients, the Associated Press reported.
The vote to expand the use of Gardasil to males was not unexpected among health experts.
"It is really hard to get a read on these things, but I don't think anybody is going to be shocked if eventually this is extended to boys, especially since the science is pretty solid here," Fred Wyand, a spokesman for the American Social Health Association, in Research Triangle Park, N.C., said before the vote.
"I would not be surprised at all if FDA approved the new indication," agreed Dr. Jonathan L. Temte, a professor of family medicine at the University of Wisconsin School of Medicine and Public Health in Madison.
Temte is also a voting member of the U.S. Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) and explained that if the FDA approves the new use for males, the CDC committee can expect to see the item on its agenda in October.
Health experts believe it makes sense to vaccinate boys against the HPV virus.
"We're supportive in general of giving vaccines to boys for a number of reasons," Wyand said. "Clinical trials have shown it's pretty effective -- 90 percent effective in preventing genital lesions [in boys]. Trials in a subset of gay men also found the vaccine to be effective in preventing external lesions, so the signs are pretty clear that it works in guys."
Vaccinating boys would help shield girls, too, the experts added.
"It's a sexually transmitted disease, and it takes two people to transmit the virus," said Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. "If the vaccine can reduce the risk of infection in men as well as women, then I believe it should be given to both men and women."
But Gardasil has generated controversy, especially with some conservatives and parents' rights groups who contend the vaccine could promote premarital sex.
Gardasil, which was approved for girls in 2006, covers four types of HPV, two of which cause about 70 percent of cervical cancers worldwide.
Since its approval, Gardasil has proven to be safe and nearly 100 percent effective in preventing precancerous cervical lesions from the four HPV strains targeted by the vaccine, according to studies. However, there have been side effects reported that include fainting and blood clotting. Research published last month found that for every 100,000 doses of HPV vaccine distributed, there were 8.2 episodes of fainting and 0.2 episodes involving blood clotting.
Studies have also found that Gardasil is much more effective when given to girls or young women before they become sexually active.
"The reason you give this is to prevent disease, and that's why we start at 11 or 12, before girls are sexually active," said Dr. Lolita McDavid, medical director of Child Advocacy and Protection at University Hospitals Case Medical Center in Cleveland. "About 10,000 American women will get cervical cancer in a year; about 3,700 are going to die from it."
"About 250,000 new case of genital warts appear in males every year," she added. "There certainly seems to be a benefit for males."
Experts hope that making the vaccine available for boys will have additional, non-medical benefits.
"Countless studies show that a lot of shame and stigma almost universally comes with any HPV diagnosis," Wyand said. "That's another factor that weighs into it. Hopefully, approving the vaccine for males would reduce any stigma."
There's more on HPV at the U.S. Centers for Disease Control and Prevention.