U.S. vaccine advisers declined to press for the use of Merck & Co's Gardasil in boys and men, opting instead on Wednesday to simply advise doctors they are free to use it.

Despite some impassioned pleas from patients and doctors alike, the Advisory Committee on Immunization Practices voted almost unanimously for permissive use of the vaccine for boys. It protects against the human papillomavirus, or HPV, which causes a variety of cancers and genital warts.

But the committee did recommend including Gardasil for eligible boys aged 9 to 18 in the Vaccines For Children program, a government-funded system that provides vaccines to children eligible for the state-federal Medicaid health insurance plan and other uninsured children.

Merck's shares were down 1.7 percent at $33.16 in afternoon trading on the New York Stock Exchange.

The U.S. Centers for Disease Control and Prevention currently recommends Gardasil for girls 11 and 12 years old and women 13 to 26 who have not been vaccinated.

Earlier this month, the U.S. Food and Drug Administration approved Gardasil for preventing genital warts in boys and men ages 9 through 26.

The main reason the vaccine was approved was to prevent cervical cancer, which kills 4,000 women a year in the United States alone. But various strains of HPV also cause disfiguring genital warts, anal and penile cancers and head and neck cancers.

We know that the later the cancer is discovered, the lower the chance of survival is, David Hastings of the Oral Cancer Foundation told the committee, asking for a recommendation to add the vaccine to the standard schedule for boys.

However, ACIP decided only to consider its use based on its ability to prevent genital warts. There, the costs did not seem to justify using a $360 vaccine.

They are sending a, very unfortunately in my opinion, weak message to physicians, said Dr. William Schaffner of Vanderbilt University in Tennessee and member of the National Foundation for Infectious Diseases.

But Dr. Diane Solomon of the National Cancer Institute said ACIP had an obligation for responsible stewardship of taxpayer money. I think it is important to communicate to industry that we are not going to blithely indicate excessive costs, Solomon said.

Gardasil, sold as a series of three vaccines, had global sales of $1.4 billion in 2008, with an additional $865 million received through a joint venture with Sanofi-Aventis SA.

Earlier on Wednesday, the ACIP voted to recommend the use of GlaxoSmithKline Plc's rival Cervarix vaccine for routine administration among girls 11 and 12 years old.

ACIP members said they doubted many insurers would cover HPV vaccines for boys.

Merck said it was planning a rebate program before the end of the year. The rebate program for Gardasil enables eligible privately insured 19-26 year olds whose out-of-pocket costs are over $30 to receive a rebate from Merck for up to a maximum of $130 per dose, the company said in a statement.

Merck & Co. Medicine