Last June a new vaccine hit the market to protect women against a cervical cancer caused by the sexually transmitted disease human papillomavirus [pap-ih-LOH-mah], or H-P-V. Now, early research finds that the vaccine may protect men against another potentially fatal disease, anal cancer.

More than six million people in the United States are infected with H-P-V annually, making it the most common sexually transmitted disease in the country. Merck’s Gardasil [guard-ah-sill] vaccine protects against four types of H-P-V, which cause seventy percent of cervical cancers and ninety percent of genital warts. The Food and Drug Administration licensed the vaccine for use in girls and women ages nine to twenty-six. It’s administered though a series of three shots over a six-month period.

Studies of the H-P-V vaccine have indicated it is extremely effective against infections from some of the viral strains that cause anal cancer. Australia and the European Union have approved the vaccine for boys ages nine to fifteen. According to the Centers for Disease Control and Prevention, vaccinating boys and men might have other health benefits, too, such as preventing genital warts. And doing so might also have indirect health benefits for women. Its ability to prevent infection in adult men, however, has not yet been shown. Studies are ongoing.

Meanwhile, doctors in the U-S can provide the vaccine to any of their patients for uses considered off label. F-D-A approval is still required, however, before the vaccine could be marketed to men as well.