Health Organization and helping develop and implement vaccine policies in the U.S. and abroad. In recognition of her work on HPV, as well as her clinical excellence, she was recently named the 2006 New Hampshire Family Physician of the Year.

"I often think I am the luckiest person in the world," Harper says, "to have my research turn out to really make a difference . . .to really change the world."

One might easily mistake Harper for an artist or an actress—almost anything but the serious physician-scientist that she is. She loves to wear bright colors, gauzy fabrics, and bold jewelry. At six feet, three inches tall, she attracts attention just by walking into a room. And she's funny, too. When she reminisces about what it was like to attend male-dominated MIT in the late 1970s, she says, "The guys at MIT—some of them don't shower, and when they talk about curves, it's all sine waves."

Harper chose MIT in part to jump out of the nearly all-female environment she had come from. She has one sister and no brothers and since pre-kindergarten had attended an all-girls private school in Kansas City, where she grew up. "I think I probably over jumped" by going to MIT, she confesses. But Harper did meet her husband of 24 years there. She describes him as "a computer geek [but] a good guy." He followed her from MIT to the University of Kansas Medical School, where she earned her M.D., did her residency in family medicine, and joined the faculty. In 1996, when Harper was offered a faculty post at Dartmouth, she and her husband moved with their two sons to Hanover, N.H.

Harper's jazzy, outgoing exterior and analytical, scientific mind make her a sought-after speaker. She charms audiences with her enthusiasm and challenges them with her broad knowledge of HPV and the HPV vaccines. In the U.S., she tells them, about 10% of the population has a high- risk anogenital HPV infection at any given time. However, she explains, the individuals who make up that 10%—men

and women alike—change continuously, as some naturally clear the virus and others become infected. HPV prevalence rates vary dramatically worldwide, she continues, from less than 5% in some countries to 30% or more in others. Scientists don't understand all the ways that HPV is spread, although most of the research has focused on the virus as a sexually transmitted infection. But "we need to look at other skin-to-skin methods of transmission," Harper argues. Doing so could open up "a whole new area of epidemiology."

With regard to the vaccines, Harper is simultaneously their biggest proponent and biggest critic. "If every single woman had this vaccine," she says, "we could eliminate HPV-associated diseases, which include cervical cancer, penile cancer, anal cancer, vaginal cancer . . . and external genital warts." But in her next breath she says, "It's not a panacea. It has its caveats."

For instance, the vaccines do not work in anyone who is currently infected. Their efficacy has been proven only in 16- to 26- year-old women, although Merck's vaccine is approved for 9- to 26-year-olds. It is not known if the vaccines' effect lasts more than five years. And even

with a widespread, mandatory vaccination program, there's "a maximum worst-case scenario of [a] 50% failure" to prevent cervical cancer because of population characteristics of HPV and of cancers caused by other strains, Harper says.

Yet despite the limitations of the new vaccines, Harper supports their widespread use and believes that insurance companies should cover them. The vaccines—Merck's requires three shots that cost about $120 each—will be cost-effective, she says, "not necessarily in reducing the numbers of cancers in the U.S., but in reducing the whole abnormal Pap smear" cycle of follow-up tests and treatments. "All of that becomes extraordinarily expensive," she explains.

Harper's concern extends beyond economics, too. She sees the vaccines as a way to spare her own patients, plus thousands of other women, the psychological trauma of learning they have HPV—usually assumed to be a sexually transmitted infection—not to mention the physical pain of follow-up tests and treatments. Cervical biopsies, for example, can be painful for women. "I walk out of the room doubled over" after performing biopsies, says Harper, "because I have such sympathetic pain for these women."

The compassion that Harper feels for her patients—and that she felt many years ago for her mother—is part of what drives her efforts to improve women's health around the world. (View this article's for several videos in which Harper discusses HPV infection, as well as the benefits and limitations of the new vaccines against it.)

When she looks back on the "tiny, detailed work" that she did back when she was a graduate student at MIT, she marvels at where she is today. While she imagines that her master's thesis on polymers is collecting dust on a shelf somewhere, a vaccine that she helped to develop may soon prevent suffering in hundreds of thousands of women around the world. "It is really a dream," she says, "to be able to know that what you worked on really is going to matter."