"One less!" shouts the Gardasil advertising campaign slogan, and teen girls seem to be listening.

More than a quarter of all teenage California girls received at least one human papillomavirus vaccination shot in 2007, according to data from the California Health Interview Survey.

The survey, conducted by the UCLA Center for Health Policy Research found that about 26 percent of girls in California between the ages of 13 and 17 had had one of the shots. The 2007 survey covered 53,611 California households, including approximately 4,000 adolescent males and females.

Gardasil is a vaccine that fights against the human papillomavirus, which causes genital warts and cervical cancer. The vaccine fights against four strains of HPV, two of which cause 70 percent of cervical cancer, along with 90 percent of genital wart cases in women.

"This is a pretty exciting kind of medicine," said David Grant, director of the California Health Interview Survey. "I don't think there is anything that you can compare it to. Other [vaccinations] don't have the same promise or excitement as [Gardasil]."

Gardasil was approved in 2006 and in 2007 the Centers for Disease Control and Prevention recommended preteens, teens and all sexually active women start the three-shot vaccination process.

Gardasil is the only HPV vaccine that has been approved in the U.S., but the long-term effects are still unknown, said Maureen Greenhagen, nursing manager at Cowell Student Health Center.

"The question for the vaccine is, 'How long is it going to last?' They don't know that. It's not clear," Greenhagen said.

In Davis, 480 women came into the Cowell Student Health Center for the HPV vaccination during the 2007-2008 school year, Greenhagen said, but not all University of California-Davis women use the campus facility to receive their shots.

"[Gardasil] is the best thing out there for preventing HPV," she said. "HPV is very common in college health.… Studies have shown [Gardasil] is very effective."

Though effective against four strains of the sexually transmitted HPV, the vaccine is still costly. Three shots are recommended for full coverage. Each shot costs $125, adding up to just under $400 for the full series.

Merck, the pharmaceutical manufacturer of the Gardasil vaccination, provides patient-assistance programs to help with the cost, and these programs are open to college students, said spokesperson Steven Cooper.

Cooper attributes the success of the fairly recently marketed drug to public relations efforts, consumer education and good communication with the medical field.

"[Gardasil] is the first ever vaccine to protect against a form of cancer," said Cooper. "[It's] a pretty important health message."

The message is getting across with Gardasil's "One less" ad campaign. California Health Survey director Grant said Merck is investing a lot into their Gardasil media campaign.

"The media campaign has definitely helped," said Grant, of the vaccine's quick popularity.

This story was filed by UWIRE, which offers reporting from more than 800 colleges and universities worldwide. Read more at www.uwire.com.