While Gardasil, the cervical cancer vaccine geared toward young women ages 9 to 26, is cost-effective for young teens, it may not be for women in their 20s, according to a new report from the Harvard School of Public Health in Boston. By using computerized models and economic measures and factoring in costs of doctor visits, screenings and checkups, researchers found that the earlier a female patient is vaccinated, the better the odds that she will avoid cervical disease caused by the human papillomavirus (HPV), thus lowering future health care costs.

The contention is that the older a woman is, the more likely it is she has already come into contact with HPV. Health officials say it’s best to give the shots to girls at age 11 or 12, before they begin having sex—but many parents have expressed their concern that this may be too early or that the vaccine may encourage sexual activity.

Gardasil—created by Merck and licensed in 2006—requires three doses over a six-month period and costs about $375. Physicians believe that the vaccine protects women against two types of the sexually transmitted HPV, thought to be responsible for about 70 percent of cervical cancer cases, and two other types that cause most genital warts.

Are you on the fence about Gardasil?  Read RH’s “Is Gardasil Good Enough for Your Girls?” to learn more.