Although Merck's HPV vaccine Gardasil is currently approved only for women between the ages of nine and twenty-six, several new studies suggest the vaccine could be beneficial for older women and even men. But should everyone who could potentially benefit from the vaccine be categorically encouraged to receive it -- especially considering Gardasil's high price tag?
A recent study used a mathematical model to show that vaccinating forty-five-year-old women in the U.S. with Gardasil could reduce their cases of cervical cancer by 55% (assuming near-impossible 100% vaccination rates). But thanks to the widespread use of pap smears in this country, the risk of dying from cervical cancer is already 70% lower than it was in the mid-twentieth century. And because Gardasil does not protect against all the HPV strains that cause cervical cancer, even women who get the vaccine should undergo annual pap smears.
In addition to pap smears, women over thirty should receive an HPV test, which detects the strains of HPV that can cause cervical cancer. This test is a huge boon to early detection of even precancerous lesions and remains a cost-effective way reduce the illness and death associated with cervical cancer -- without the need to extend expensive Gardasil shots to all women.
In light of a new study indicating that Gardasil may be effective in boys and young men, launching a campaign to encourage them to be vaccinated is a wise public health decision. Researchers concluded that the vaccine was 90% effective for men at preventing genital warts caused by HPV and 45% effective at protecting them from the four strains of HPV the vaccine inoculates against.
More studies need to be done on whether vaccinating men with Gardasil protects their female sexual partners from contracting HPV, but if it does, it would be a strong argument to encourage them to get the shots. As Dr. Mark Goldstein, a specialist in adolescent medicine at Mass General, told Boston's WBZ-TV, "Girls, by and large, get HPV from boys...[Boys] certainly have a responsibility for contraception, so I do think they have a responsibility in the prevention of HPV infection in females."
Additionally, HPV was recently linked to certain cancers in men, namely anal cancer, penile cancer, and cancers of the mouth and throat. Vaccinating both male and female adolescents with Gardasil could eventually increase herd immunity to a point where cancers caused by HPV are no longer a significant threat.
But we face a more pressing priority than expanding the pool of people eligible to receive Gardasil -- making sure that girls and young women in developing countries receive the vaccine. While pap smears and HPV tests have dramatically cut an American woman's chance of dying from cervical cancer, the disease remains the leading cause of cancer deaths among women in a majority of developing countries -- who account for 85% of its yearly cases.
Making Gardasil available and affordable around the world -- especially in places where women don't have reliable access to quality health care (and where yearly pap smears, let alone effective treatments for late-stage cervical cancer, are virtually impossible to come by) -- is the most important public health initiative we can take regarding this potentially life-saving vaccine.
Elizabeth Wade is an ACSH research intern and will blog more about Gardasil and HPV next week.