Paul Hoppe

The new vaccine against a potentially deadly sexually transmitted infection (or STI, as they're known) is one of the hottest topics in public health right now. Last month the U. S. Food and Drug Administration (FDA) approved the use of Gardasil, the first vaccine against the human papillomavirus (HPV)—a virus whose most commonly known symptom is genital warts—for women and girls ages 9 to 26. The approval was a clear victory for women's health and a rebuke to misguided social conservatives, who have an annoying habit of putting up roadblocks every time public policy tries to address the fact that people have sex. Then on June 29, in another long-overdue liberal victory, the Centers for Disease Control and Prevention (CDC) recommended that all 11- and 12-year-old girls receive the vaccine. The story of the vaccine's development, however, stretches back over a century and a half, to an obscure Italian medical-journal article about nuns. And—long before it reached the halls of the FDA and CDC—the vaccine trials were designed here in Seattle, by University of Washington professor Dr. Laura Koutsky.

Unlike many other pathogens for which vaccines have been successfully developed, HPV isn't a particularly flashy virus. It doesn't paralyze your limbs, like polio, or turn your skin yellow, like hepatitis. Its symptoms are hard to detect, when they even appear at all. At the same time, it's extremely pervasive. According to the CDC, a whopping 80 percent of U.S. women will have contracted some form of HPV by the age of 50—making it the most common sexually transmitted infection. HPV is also prevalent in men, though there's currently no clinical test available to indicate a man has been infected.

Some types of HPV cause genital warts; others lead to mild Pap-test abnormalities but display no outward symptoms. Most infections with a low-risk strain of HPV resolve themselves on their own and are never heard from again, but in a minority of cases HPV leads to cervical cancer. In the U.S., the American Cancer Society predicts 9,710 new cases of cervical cancer will be diagnosed this year (many more cases will be recognized in precancerous stages thanks to Pap smears), and 3,700 women will die from the disease. Worldwide, cervical cancer causes 290,000 deaths annually, mostly in developing countries where women don't have access to preventative screenings.

Koutsky is an epidemiologist at the University of Washington, and has been studying HPV for 15 years. Before she'd even earned her PhD, she worked as a research assistant to UW professor of medicine Dr. King Holmes, a high-profile figure in the field of HIV/AIDS treatment and prevention. After some initial independent research on chlamydia and herpes, she began studying HPV in earnest, charting the natural history of HPV infection ("who gets it, what age they're getting infected, how soon after they're infected do they get the disease"), and laying the groundwork for an eventual vaccine. In the late 1990s, when Merck pharmaceutical company scientists were putting the finishing touches on their HPV vaccine, the company approached her about designing and running the international vaccine trials—which ultimately involved some 20,000 women, including 780 here in Seattle.

After years of research and testing, last month Merck debuted its HPV vaccine, which protects against four strains of HPV: 16 and 18 (which together account for 70 percent of all cervical-cancer cases) as well as 6 and 11 (accounting for between 80–90 percent of all genital warts). Because Gardasil doesn't protect against all the strains of HPV that have been linked to cancer, and won't treat preexisting infections, Koutsky emphasized that women still need to have regular Pap tests. Currently, the vaccine costs $360 for a three-dose course, but it will be available to low-income minors through the Vaccines for Children Program.

According to Koutsky, the correlation between cervical cancer and a sexually transmitted pathogen was first suggested by data collected in the 19th century. Domenico Antonio Rigoni-Stern, a statistician with the morbid duty of perusing death certificates, noticed an odd discrepancy in cancer rates for women of various social positions. He published his findings in a now-famous 1842 article: Compared to married women, celibate nuns had a much lower rate of cervical cancer and a higher incidence of breast cancer.

Contemporary academics have disputed some of Rigoni-Stern's results (one recent journal article can basically be summarized, "Nuns do too get cervical cancer! Don't skimp on their Pap tests!"), but his observations fit with what researchers have since learned about these diseases. Breastfeeding slightly decreases your chances of getting breast cancer. And cervical cancer occurs only in women carrying certain strains of sexually transmitted HPV. Those 19th-century nuns were a sort of accidental control group: If you don't have sex, you don't contract HPV, and you don't get cervical cancer.

But not every woman can live like a nun. So from a public-health perspective, it made sense to try to find a way to protect against the virus itself. It wasn't until the 1970s, Koutsky explained, that scientists had access to the DNA-based technologies that would make an HPV vaccine feasible. But once a parallel vaccine was successfully developed for canine papillomavirus in beagles ("If puppies get oral warts," Koutsky observed dryly, "they're hard to sell"), a vaccine for human papillomavirus was within reach.

In a political climate where any public-health policy that acknowledges that adults (and many teenagers) have sex outside of marriage is at risk of being crushed by ideology, a vaccine against HPV could have set off a firestorm. The powerful Christian lobbying group Focus on the Family, for example, "affirms—above any available health intervention—abstinence until marriage and faithfulness after marriage as the best and primary practice in preventing HPV." But there was barely a peep from social conservatives when the FDA endorsed the safety and efficacy of Gardasil on June 8. The June 29 CDC recommendation that all 11- and 12-year-old girls be vaccinated was unanimous.

The smooth rollout of the first HPV vaccine has been a public-health triumph. There were initial rumblings from social conservatives, but prominent right-wing organizations decided not to lobby against approval of the vaccine. Does this mean the religious right is suddenly amenable to scientific progress? Does it portend sensible compromises that usher fact-based sex education into classrooms currently locked into an abstinence-only curriculum? Will opposition to emergency contraception dissolve, given the potential to reduce costly and invasive abortions?

These things would be nice. But the HPV vaccine probably owes its success to a unique marketing niche. Scientists were able to demonstrate to the public the clear connection between the virus and cervical cancer. That word "cancer" was key. Conservatives often win culture wars because they're so good at simplifying the issues: life, taxes. This time, liberals held the power of the simple message: cancer, death. Little kids grow up telling their teachers they want to cure cancer, suburban mothers walk to support cancer research, and everyone knows someone who has been affected by the disease. Social conservatives could hardly oppose the vaccine—unless they wanted to advocate the spread of cancer.

That doesn't necessarily mean they're going to inoculate their own children. As Koutsky pointed out, "Parents who are confident that their children are not going to have sex until they're married may opt out of it." Such opt-out provisions exist in all 50 states. But Koutsky is a savvy pragmatist: "The bottom line is that it usually tends to be a very small minority of parents who make that decision." That's a small price to pay for making a revolutionary cancer vaccine available to the rest of us. recommended