Washington, DC (AHN)-The first vaccine to protect against most cervical cancer won federal approval Thursday.

Merck and Co. Inc. says the vaccine Gardasil, approved for use in girls and women ages 9 to 26, prevents infection by four strains of the human papillomavirus, or HPV, the most prevalent sexually transmitted disease.

According to the Reuters report, Merck is expected to market Gardasil as a cancer, rather than an STD, vaccine. The cervical cancer HPV kills about 290,000 women worldwide each year, including 3,700 in the United States. In the U.S., regular Pap smears often detect precancerous lesions and early cancer, however, the vaccine does not eliminate the need for regular screening.

On a separate note, analysts believe Gardasil sales could top $1 billion a year for Merck, which is battling thousands of lawsuits over its withdrawn painkiller Vioxx.