Among the more than 100 types of human papillomavirus (HPV), about a dozen cause cervical, anal, genital and mouth and throat cancers. Pap smears have dramatically lowered cervical cancer deaths by catching HPV-triggered precancerous cell changes before they turn into cancer. But vaccines can prevent young people from contracting the virus in the first place.

The first HPV vaccines, which have been around for about a decade, protect against only two cancer-causing HPV types (16 and 18). In 2014, the Food and Drug Administration approved Gardasil 9, which wards off five additional high-risk types (31, 33, 45, 52 and 58).

Long-term results from a study of more than 14,000 women, recently published in The Lancet, showed that those who used Gardasil 9 had lower rates of infection with these added HPV types, as well as fewer abnormal cervical cell changes, precancerous lesions and procedures to stop disease progression. The researchers estimate that the vaccine could potentially prevent 90 percent of cervical cancer cases worldwide.

“There is no question that the vaccine works,” said study author Warner Huh, MD, of the University of Alabama at Birmingham. “The challenge is to get the new vaccine into widespread use among young women.”

But women are not the only ones who stand to benefit. As cervical cancer declines, rates of HPV-related anal and oral cancers are on the rise, with the number of non-cervical cancers now nearly matching that of cervical cancers, according to the National Cancer Institute. Most of these are occurring in men, who don’t benefit from routine screening. The Centers for Disease Control and Prevention recommends HPV vaccination for both boys and girls at age 11 or 12, with eligibility extending through age 26. But nationwide, 40 percent of adolescents still have not received the vaccine.