January is cervical cancer awareness month, which, at first, doesn’t seem like it would have much to do with boys. After all, the disease only strikes women. But the Food and Drug Association’s recent approval of Gardasil, a vaccine that prevents the virus that causes cervical cancer, has some doctors and researchers asking, “So where do the boys come in?”
The virus that causes cervical cancer, human papillomavirus (HPV), also causes genital warts in either gender and is transmitted through sexual contact. HPV is also behind several rare forms of cancer in men. But Gardasil is now being administered nationally only to girls ages 9 to 26.
Vaccination programs aim for herd immunity, which means immunity in a population is so high that infections cannot spread. Immunizing all girls would achieve herd immunity, but due to hesitation by parents who object to vaccines in general as well as those who oppose the Gardasil vaccine specifically (some parents object to having their daughters immunized against a sexually transmitted disease), not enough girls may get the vaccine.
An editorial in the British medical journal The Lancet last October said that data from vaccine trials suggest a female-specific approach would only be between 60 and 75 percent as effective at reducing HPV as strategies that target both sexes.
Dr. Bess Gold, a pediatrician with Pediatric Services in St. Louis Park, says she expects a cost-benefit analysis will be done to assess whether the cost of immunizing males will benefit the health of society as a whole once the vaccine is approved for males.
“Theoretically, if all women get immunized, they wouldn’t catch the virus from an infected male,” explains Gold. “But I don’t think any man wants to think he could potentially spread a virus like that to his partner if she’s unvaccinated.”
Merck and Co., which produces Gardasil, studied the effectiveness of the vaccine on both males and females as part of the regulatory submission to the FDA, but the larger efficacy studies were focused on females because the majority of HPV diseases affect women.
“Our goal was to be able to first provide benefit to the largest group of people possible that could potentially be affected by HPV disease, knowing that we would continue to study the vaccine further in additional patient populations,” says Deb Wambold, a spokesperson from Merck’s vaccines public affairs office.
Today, Merck has several ongoing studies involving the benefit of Gardasil for males, and Wambold says the results should be completed by 2008. That means vaccinating males is still several years off in the United States (Australia has already approved Gardasil for males) but, based on the benefits it will provide for both sexes, Wambold says it will be the natural next step in vaccinations. “We believe that males are an important population to vaccinate. The thought is that if we can demonstrate prevention of HPV infection in males, then we can help protect women as well.”