Boys should routinely be vaccinated against the sexually transmitted human papillomavirus (HPV) at age 11 or 12 to protect them against genital warts and certain cancers and to reduce the chances that they will spread the virus, a federal advisory panel recommended Tuesday.

The Advisory Committee on Immunization Practices (ACIP), which helps set standards for childhood and other vaccinations, voted overwhelmingly to bring the recommendation for boys in line with that for girls. The vote was 13 in favor and none opposed, with one member abstaining.

Since 2006, federal officials have recommended that girls be vaccinated at 11 or 12 to help reduce their risk of cervical cancer. The vaccine was approved for boys in 2009, but previous guidelines did not call for their routine vaccination.

Citing additional data on the vaccine’s safety and ability to prevent precancerous growths, the committee recommended boys could begin receiving the Gardasil vaccine for HPV as early as 9. Boys 13 to 21 who have not been vaccinated should get “catch-up” shots, the panel added in a separate vote of 8 to 5.

“Today is another milestone in the nation’s battle against cancer,” said Anne Schuchat, director of the National Center for Immunization and Respiratory Diseases at the federal Centers for Disease Control and Prevention in Atlanta, which will issue a final set of recommendations.

The agency’s recommendations play a crucial role in encouraging vaccine use. Doctors tend to follow the agency’s guidelines, and insurance companies use the information to decide which vaccines to cover. The new federal health law requires insurers in new exchanges to provide recommended vaccines. Gardasil requires three vaccine doses that cost about $400 total.

The vaccine protects against HPV, which is the most common sexually transmitted infection. An estimated 20 million Americans are infected with HPV. For most people, the virus never causes problems. But it can cause genital warts, which in women can lead to cervical cancer — a disease that strikes about 12,000 American women a year and kills about 4,000. The virus causes perhaps an additional 6,000 cases of cancer of the vulva, head and neck in females each year.

Among males, the vaccine is aimed at protecting against genital warts and less-common malignancies that HPV can cause, such as cancer of the mouth, throat and anus. The virus causes at least 250,000 new cases of genital warts and an estimated 7,000 cancers in males each year, leading to perhaps about 1,000 deaths.

Vaccinating boys and men would also help prevent the spread of the virus to sexual partners. Gay men, particularly those infected with the AIDS virus, are especially at risk.

In 2006, the Food and Drug Administration approved Gardasil for girls as young as 9. Medical authorities then recommended that girls be vaccinated at 11 or 12, to protect them before they start having intercourse. Critics worried that vaccinating children would send a subtle signal that their parents were assuming they would become sexually active and give youngsters a false sense of security.

Merck, which makes the vaccine, began an ambitious marketing and lobbying campaign to persuade states to add the injections to the list of those required for children to attend school. But the company abandoned the strategy in the face of an intense backlash from those who argued that the decision should be left to parents. Only Virginia and the District imposed a mandate.

Texas Gov. Rick Perry, who is running for the Republican presidential nomination, has been criticized for attempting to mandate the vaccine for girls in his state. Rep. Michele Bachmann (Minn.), one of Perry’s rivals for the nomination, stirred controversy in September when she suggested the vaccine can cause mental retardation. That suggestion was immediately dismissed by leading health authorities.

Federal health officials and others say they are confident that the vaccine is safe. Public health experts have been disappointed by resistance. Only about half of adolescent girls in 2010 had received at least the first of the recommended three HPV shots and about one-third had received all three doses. Only about 1 percent of males have been vaccinated.

Merck praised the panel’s decision.

“These new recommendations for use in males mark another important step in helping to protect more people from the HPV-related diseases that Gardasil is indicated to prevent,” Mark Feinberg, Merck’s chief public health and science officer, said in a statement.

Some experts, however, are concerned that there is insufficient evidence about how long Gardasil’s protection will last, whether serious side effects will emerge and whether the relatively modest benefits for boys are worth even the small risks associated with any vaccine. They noted that so far the vaccine has only been shown to reduce the risk of developing pre-cancerous growths, not cancer itself.

“Parents need to carefully consider the benefit-harm ratio in vaccinating their male children,” said Diane M. Harper, a professor of medicine at the University of Missouri at Kansas City who helped study the vaccine in women for Merck. “Hopefully this news will not be shared with parents in a fear-inducing manner, but that the real risks of disease will be discussed including the rare possibility of side effects. It is more important to spend those health-care dollars in obesity-fighting programs than to prevent HPV in boys.”