Vaccine May Pack More Cancer-Preventing Power
Susan Yara, 06.16.06, 12:30 AM ET Forbes.com

Thousands of American women could live longer now that the Food and Drug Administration has approved a vaccine for a very common sexually-transmitted disease, human papillomavirus infection. And though most of the attention has focused on the vaccine's appropriateness for young women, doctors say it has the potential to help post-adolescents as well.

HPV is the major cause of cervical cancer, which kills almost 4,000 women in the United States and nearly 250,000 worldwide each year, according to the National Cancer Institute. HPV is also incredibly widespread. Wendy Everett, president of the New England Healthcare Institute, a health policy research organization in Cambridge, Mass., estimates that about 80% of women will contract HPV by the time they are 50.

They likely won't even know it. Scientists have identified 100 different strains of HPV. Most kinds cause no symptoms and clear on their own within two years of infection, says Dr. Oleg Bess, who runs a private practice in Beverly Hills, Calif.

But, about a dozen "high-risk" HPV strains can cause cervical cancer. Merck's vaccine Gardasil produces immunity against four strains of the virus: HPV 6 and 11, which account for 95% of genital warts cases, and HPV 16 and 18, which account for 70% of cervical cancer cases.

Since the vaccine has so far only been shown to work against strains that women have not been exposed to, Gardasil is meant to be a preventative measure for those who have not yet become sexually active. "Anyone who has had sex has been exposed to HPV," says Dr. Mary Fatehi, a gynecological oncologist at Long Island College Hospital in Brooklyn, N.Y. "And once the DNA from the virus gets integrated with a personís DNA, itís extremely hard to detect."

That's why the FDA is recommending the vaccine series, which comprises three shots given over six months, for women between the ages of 11 and 26. But that doesn't mean that women who are sexually active should not try it.

Fatehi says there is virtually no downside to receiving the shots, and that studies not yet published show they could potentially aide the body in producing antibodies against the virus.

"This could be beneficial for women who already have HPV," she says.

Dr. Oleg Bess, a gynecologist who runs a private practice in Beverly Hills, Calif., agrees. "Most women who are already infected have only one type of HPV, therefore administering the vaccine will protect them from the other types," he says.

The HPV vaccine has the potential to nearly abolish the virus, not to mention reduce the amount of money spent on pap screenings and other diagnostic tests.

"Currently the cost of screening and prevention [for cervical cancer] is at about $6 billion [annually] in the U.S.," Everett says. "The vaccine will cost about $500, so this is a huge public health achievement."