HPV vaccine for women and men

Preventing cancer in thousands of Americans every year is a good thing, right? When one examines the case of the new HPV vaccine in the United States, the unexpected answer appears to be, "not yet, maybe later." If you are unlucky enough to be a woman over the age of 26 or even unluckier to be a man, you are currently most likely missing out on getting this vaccine. And you shouldn't.

Since the introduction of the vaccine that protects against the most troublesome strains of the HPV virus in 2006, young women have been lining up to get it and with good reason: HPV is a necessary condition for the development of cervical cancer which kills more than 3,500 women every year in the United States alone.

Initial studies of the vaccine have only focused on women up to 26 years of age. This explains why the FDA approval and current marketing efforts are restricted to women up to that age. This restriction is almost certain to be relaxed as more clinical trials are being conducted. But this may be years away. In the meantime, the vaccine could prevent many more HPV infections if it was more widely known what a tremendous health threat HPV can be — to both men and women who are sexually active with partners of unknown HPV status.

In 1996, Harald zur Hausen, the father of HPV research, identified HPV as "a major cause of human cancers." Since then, cancer researchers have conducted numerous studies linking HPV to many types of cancer. For some types, the link is firm and strong, but for others the scientific debate is still ongoing.

Anal cancer is largely caused by HPV and gay men are particularly at risk. While the incidence of anal cancer in the general population is only 1.5 per 100,000 people per year, the most widely cited incidence for men who have sex with men (MSM) is 35 out of 100,000 people per year. This implies that the anal cancer risk for MSM is several times higher than the cervical cancer risk for women and at least one order of magnitude higher than the anal cancer risk for non-MSM.

The vaccine is badly needed for the prevention of anal cancer because classic cervical cancer prevention protocols (pap smears) are not standard for anal cancer. Even when anal pap smears are practiced, achieving permanent treatment success for anal lesions has been challenging.

If you are still not sure if you need the HPV vaccine because you are a straight male here is the argument for you: Researchers have established a causal relationship between HPV and certain types of mouth and throat cancer. Last May, a study published in the New England Journal of Medicine made headlines showing a statistical association between the presence of oral HPV infection and a certain type of throat cancer. The article was also able to provide evidence for a particular transmission mechanism: oral sex.

According to the American Cancer Society, HPV may be a factor in the development of around 20 to 30 percent of the estimated 34,360 cases of mouth and throat cancer occurring in the United States in 2007. Ironically, this type of cancer is more common in men than in woman. Researchers fear that vaccination programs limited to females will only delay the potential benefit in the prevention of mouth and throat cancers.

The good news is that the prophylactic effect of the available HPV vaccine in older women and in men is undisputed. The vaccine has already been approved for boys in some countries, and leading HPV researchers are advocating vaccinating boys.

Currently, women over the age of 26 and men can get the vaccine if they find a doctor who is willing to prescribe it to them. This, however, means only the lucky few who know about the broader significance of HPV, who manage to find a knowledgeable and cooperative physician and who can afford to pay the cost of $400 or more will get it. These barriers to getting the vaccine will over time cost many thousands of lives in this country. Make sure it's not yours! At Princeton, all students can get the vaccine at Student Health Services. Johannes Enders is an Operations Research & Financial Engineering graduate student. She can be reached at jenders@princeton.edu.