A vaccine that protects against the sexually transmitted human papillomavirus should be routinely given to boys ages 11 and 12 to prevent anal cancer, a government advisory committee has decided.
Though many parents may not wish to contemplate the future sex lives of their pre-adolescent children, vaccinating them young is the best way to avoid the risk of the cancer-causing virus, experts said Tuesday.
The recommendation is sure to ignite further debate among the Republican presidential candidates who have focused intently on whether the controversial vaccine, called Gardasil, is appropriate for girls — who receive it for prevention of cervical cancer — let alone for boys.
Texas Gov. Rick Perry was criticized by his GOP rivals for ordering mandatory HPV vaccination for girls in his state in 2007. The mandate was overturned by the Legislature, and Perry eventually withdrew his support for the idea.
Another Republican presidential hopeful, Minnesota Rep. Michele Bachmann, has placed Gardasil in the spotlight by suggesting that the vaccine can cause “mental retardation.”
Public health groups quickly criticized Bachmann for the remarks, and the federal Advisory Committee on Immunization Practices, prior to its Tuesday vote, took time to state for the record that the vaccine does not cause mental retardation.
The vote of 13 to 0 (with one abstention) in favor of routine HPV vaccination of boys supersedes a 2009 vote by the panel recommending Gardasil be available to males ages 9 to 26 to prevent genital warts but not recommending routine vaccinations.
Since then, several studies have shown that the human papillomavirus is responsible for many cases of anal cancer in addition to cervical cancer and genital warts, and that the vaccine can curb this risk, warranting a shift to stronger recommendations, the panel members said. The vaccination of boys also will help protect unvaccinated females, the panel added.
Gardasil, administered as a three-shot regimen, has been advised since 2006 for girls ages 11 and 12 as well as for older unvaccinated females to prevent cervical cancer.
In addition to routinely administering Gardasil to boys ages 11 and 12, the panel, which advises the Centers for Disease Control and Prevention, also advised vaccination for boys as young as age 9 and for males ages 13 to 21 who have missed the ideal vaccination age window of 11-12.
Although CDC officials do not have to follow the committee’s guidance, they often do — and a CDC vaccination recommendation is significant because health insurers typically shape their coverage to be in line with such recommendations.
“I think this is a major step forward in prevention of HPV-related cancers,” said Dr. Joel Palefsky, a professor of medicine at UC San Francisco and director of the UCSF Anal Neoplasia Clinic. Palefsky’s lab reported last year that Gardasil curbed the development of precancerous anal lesions that can evolve into cancers. He has received grants from Merck, the maker of Gardasil, and has served as an advisor to the company.
“It also serves to equalize the burden of vaccination to not just one gender — and recognizes the responsibility of both males and females,” Palefsky said.
Anal precancers are difficult to treat and there is no routine screening test for early diagnosis, as there is for cervical cancer. The four strains of HPV that Gardasil protects against account for about 90% of all cases of anal cancers, he added.
More than 5,000 cases of anal cancer are reported a year and about 700 people die from it annually, according to the American Cancer Society. Rates have doubled in the United States since 1980 and are increasing about 2% a year.
Men who have sex with men are at highest risk for anal cancer. For that reason, some health experts proposed recommending HPV vaccination only to gay or bisexual men.
But, as with girls, the vaccine would be most effective if delivered before initiation of sexual activity — and trying to target the vaccine based on sexual orientation for school-age males would be a practical and ethical morass, health experts have noted.
“A routine vaccination recommendation de-stigmatizes the vaccine and makes it likely that those people who would benefit the most will also get the vaccine,” Palefsky said.
Heterosexual men will also benefit from vaccination, in any case, by a reduction in the risk of genital warts, anal cancer and, possible, some oral cancers, he added.
In reaching their conclusions, the committee debated whether routine vaccination of boys was necessary if girls were already vaccinated. As more girls and women are vaccinated, they create a “herd immunity” effect, reducing the amount of virus that circulates in a community and thus lowering infection rates in both women and men.
However, as of 2010, only about a third of U.S. girls had received the three-dose vaccine, and the rates are plateauing, said Dr. Anne Schuchat, director of the National Center for Immunization and Respiratory Diseases.
Another potential barrier to routine use is money. The three-shot series costs at least $300.
“Year after year we continue to have evidence of low uptake in girls,” said Dr. Jane Kim, an assistant professor of health decision science at Harvard School of Public Health who has studied the cost-effectiveness of the HPV vaccine. “When we’re at such low coverage for girls, it is of value to vaccinate boys.”
It’s not clear how well parents will embrace vaccination of their adolescent sons. Those who are dubious should know that vaccination against HPV may help prevent other types of cancers, such as those of the penis, head, neck and mouth, said Dr. Jessica Kahn, associate professor of pediatrics at Cincinnati Children’s Hospital and chair of the vaccinations committee for the Society for Adolescent Health and Medicine, which supported the recommendation.
Rates of oral cancers are rising, and HPV infection is now thought to account for more cases of oral cancer than tobacco use, Kahn said.
And, she added, the vaccine is just as safe and effective in boys as in girls.
The key to acceptance, Kahn added, will be in making sure that parents understand the range of diseases that HPV can cause in their sons. The role of HPV in cervical cancer is broadly known, she said. “But we fall short in explaining what HPV can cause in boys and men.”