HPV vaccine less cost-effective after 21, study says

Vaccinating girls and young women against a sexually transmitted virus that causes cervical cancer has drawn questions about its long-term safety and effectiveness, prompting federal officials to reassure the public of its safety last month. Now, a Harvard analysis says giving the vaccine after age 21 doesn't make economic sense.

Since its approval two years ago, Gardasil, a vaccine against four strains of human papillomavirus, has been aggressively marketed by Merck, as story in today’s New York Times notes. But its price -- more than $300 -- and the fact that three doses are needed has slowed adoption of the vaccine. At the same time, questions have arisen about its usefulness compared to current screening methods.

In this week’s New England Journal of Medicine, Jane J. Kim and Dr. Sue J. Goldie of the Harvard School of Public Health evaluated the HPV vaccine’s cost-effectiveness, comparing it to Pap smears, the traditional screening method.

Based on computer models derived from economic, demographic, and clinical data, they recommend universal vaccination for 12-year-old girls and young women up to 21 years old. That varies from US Centers for Disease Control and Prevention guidelines that suggest vaccinating women as old as 26 and girls as young as 9. The authors argue that most women are sexually active past age 21, while the vaccine works best before that point.

Kim and Goldie's research was funded by the National Cancer Institute, the CDC, the American Cancer Society, and the Bill and Melinda Gates Foundation.

In an editorial published with the article, Dr. Charlotte J. Haug of the Norwegian Medical Association says the Harvard authors are optimistic about the vaccine's protection.

"If the protection of the vaccine wanes after 10 years, vaccination is much less cost-effective and screening is more effective than catch-up programs," she writes.