In October, the Food and Drug Administration expanded its approval of the Gardasil 9 human papillomavirus (HPV) vaccine for women and men ages 27 to 45. Previously, the vaccine was available only for those up to age 26.

The vaccine protects against nine different types of HPV, several of which cause cervical, anal, and mouth and throat cancers. Some studies show that oral carcinoma is now the most common HPV-linked cancer.

HPV is usually sexually transmitted, and most people pick up some of the more than 100 types soon after they start having sex. The Centers for Disease Control and Prevention recommends HPV vaccination for girls and boys at age 11 or 12, before they become sexually active.

Recent research has found that many people older than 26 have not yet been infected with all the HPV types covered by the vaccine and therefore can still be protected. One study of more than 3,000 women ages 27 to 45 showed that Gardasil 9 was 88 percent effective against persistent HPV infection, genital warts, precancerous lesions and cervical cancer caused by the nine virus types covered. There’s less research on men, but studies show they develop immunity as well as women do.

If you’re 45 or younger, ask your care provider whether the HPV vaccine is right for you.