Now that the U.S. Food and Drug Administration has approved a vaccine to protect against cervical cancer, you may have to get on a waiting list to receive it, especially if you're in your late 20s or older.

Gardasil, made by Merck & Co., received FDA approval June 8, 2006, and it's one of two vaccines that will probably be given first to those aged 10 to 26, according to Fred Wyand of the American Social Health Association, a nonprofit organization in Research Triangle Park, NC, that researches sexually transmitted diseases.      

The vaccines provide protection against a pathogen called the human papillomavirus (HPV), transmitted sexually and the culprit behind 70 percent of cervical cancers. "The idea is you'll be getting it to people who are not — for the most part — sexually active yet," he said, referring to the younger people in that age bracket.

Merck spokesperson Kelley Dougherty said Gardasil was approved for females aged 9 to 26, and added that studies were ongoing to prove the vaccine works in those up to age 45, she said.

The second vaccine, Cervarix, is under development by another large pharmaceutical company, GlaxoSmithKline.

Within three years or so, after more data is analyzed about the value of the vaccine in older persons, this vaccine will probably be recommended increasingly for older age ranges, said Dr. Diane Harper, a professor of community and family medicine and obstetrics and gynecology at Dartmouth Medical School, Lebanon, NH, and an expert in the field.

Cervical cancer is the second most common malignant disease in women worldwide, Harper noted, and is often diagnosed at a younger age than other cancers. About 9,700 new cervical cancer cases are expected in the United States this year, according to the American Cancer Society, and about 3,700 women will die from it, the association estimates.

The two new vaccines protect against HPV types 16 and 18, which account for about 70 percent of all cervical cancers. Cervarix also protects against two other HPV types, 45 and 31, which can also trigger cervical cancer, Harper reported in the British journal The Lancet earlier this year. And Gardasil also protects against HPV 6 and 11, which account for about 90 percent of genital warts, according to Merck.