CDC Advisory Committee Declines to Recommend Gardasil for Males

October 26, 2009
Christin Melton

In October 2009, the FDA approved the Gardasil vaccine to immunize men and boys against two strains of the human papillomavirus (HPV). The virus causes genital warts, though the primary concern with these strains is their relationship with cervical cancer. As Professor Jack Cuzick, head of the Centre for Epidemiology, Mathematics, and Statistics, at the Wolfson Institute in London, told attendees at the September ECCO-ESMO Congress, “It’s important to say up front that HPV is responsible for all cervix cancer. If you can eradicate the virus, the cancer will not appear.”

In October 2009, the FDA approved the Gardasil vaccine to immunize men and boys against two strains of the human papillomavirus (HPV). The virus causes genital warts, though the primary concern with these strains is their relationship with cervical cancer. As Professor Jack Cuzick, head of the Centre for Epidemiology, Mathematics, and Statistics, at the Wolfson Institute in London, told attendees at the September ECCO-ESMO Congress, “It’s important to say up front that HPV is responsible for all cervix cancer. If you can eradicate the virus, the cancer will not appear.”

Preventing cervical cancer was the primary impetus for developing an HPV vaccine; there are currently two HPV vaccines available to girls and young women in the United States: Gardasil and Cervarix. Both protect against different strains of the virus strongly associated with cervical cancer. Until now, neither vaccine was available for males, even though males can contract HPV through sex with an infected partner. In addition to genital warts, HPV can cause penile cancer in men; and in both sexes, it has been linked to anal cancers and head and neck cancers. Thus, it seemed logical to approve the vaccine for males, which the FDA did.

Yet, last week a CDC Advisory Committee on Immunization Practices declined to recommend that boys and younger men be routinely vaccinated with Gardasil, in contrast to its recommendation for girls and younger women. The rationale was that the vaccine, which costs $300 to $400 for the 3-shot series, was not cost-effective. The cancers men get that are associated with HPV are rare, and the panel said genital warts are embarrassing and uncomfortable but not life threatening.

This mirrors the findings of a study published online at the Website for the British Medical Journal earlier this month. Harvard School of Public Health Researchers found that including males in an HPV vaccination program more than doubled the cost per quality of life year (QALY) gained, from $50,000 per QALY to $100,000 per QALY. The authors said, “Our results suggest that if vaccine coverage and efficacy are high among pre-adolescent girls, including boys in an HPV program is unlikely to provide comparatively good value for resources.” An editorial written by two US researchers that accompanied the article concurred, saying, “Good coverage of females obviates the need to vaccinate boys.”

The problem with this study, which the CDC Advisory Committee embraced in making its recommendation, is that it calculates cost-effectiveness based on a premise of "75% vaccination coverage and an assumption of complete, lifelong vaccine efficacy." Currently, no state in the US requires girls to get the HPV vaccine. According to the New York Times, which cited a national immunization survey, “about 37% of girls ages 13 to 17 started the HPV vaccine series…and about half of them completed it.” In other words, less than 20% girls aged 13 to 17 years were sufficiently vaccinated in the US last year to confer long-term immunity against HPV.

Political considerations have made many states reluctant to mandate the HPV vaccine for girls, even as they require insurers to cover the cost. Some parents’ groups oppose the vaccine on moral grounds, saying it will lure girls into having premarital sex. Other groups have expressed doubts about evidence that the vaccine is safe.

Last year, the CDC reported that immunization compliance in the United States had dropped from 81% down to 72%. They attributed it to confusion over complicated vaccination schedules and vaccine shortages. In March 2009, the California Department of Public Health’s Center for Infectious Diseases reported that the number of parents requesting to exempt their school-aged children from vaccines had doubled since 1997. In at least 20 states, parents merely have to fill out a form to exempt their children from the mandated vaccinations based on "philosophical" reasons—a practice that has escalated as unsubstantiated fears about a link between vaccinations and autism continue to percolate combined with a growing distrust of vaccines in general.

Unless legislators are willing to face the wrath of these groups and require that girls be vaccinated as a condition for attending school, the desired herd immunity is not likely to be realized. Merck, the maker of Gardasil, argues that vaccinating boys will reduce the number of females who contract HPV through sex, contributing to further declines in cervical cancer rates and increasing the vaccine’s cost-effectiveness for boys. Merck also says the savings generated just from preventing the 200,000 or so cases of genital warts in younger males justifies the vaccine’s expense.

The CDC Advisory Committee’s decision makes it less likely that government health programs and private insurers will cover the vaccine for boys. For now, this leaves it up to parents to decide whether they want to purchase the vaccine for their sons.