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Confused About Who Should Get the HPV Vaccine, and When? The CDC Has New Recommendations

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For its first few years on the market, the human papillomavirus (HPV) vaccine was approved only for young girls. Over time, the U.S. Food and Drug Administration (FDA) has broadened its approval to include boys, as well as adults up to age 45—allowing more people to get the cancer-preventing vaccine, but also breeding confusion about who should get vaccinated and when.

On Thursday, the U.S. Centers for Disease Control and Prevention (CDC) released new recommendations, based on guidance from the Advisory Committee on Immunization Practices, that should clear up some of that confusion. The CDC reaffirmed that its prior recommendations for kids stand: boys and girls should get their first dose of the HPV vaccine when they are 11 or 12 years old, and a second dose six to 12 months later. If they do not get vaccinated on time, “catch-up vaccination” should be completed by the time they turn 26, the CDC now recommends.

After age 26, however, the CDC says most unvaccinated adults do not need to get the shot—even though it is safe and approved for people up to age 45. That’s because the preventative vaccine is most effective among people who have not already been exposed to HPV, a very common sexually transmitted infection that’s usually harmless, but can lead to cervical and other cancers. Most people have already come into contact with HPV by their late twenties and potentially developed immunity naturally, rendering the vaccine less necessary. (The shot can also only prevent new infections, not slow the progression of existing ones.)

Doctors can help individual adult patients decide whether they may benefit from HPV vaccination after age 26, the new recommendations say. Having new sexual partners is a risk factor for HPV transmission, so that likelihood should be taken into consideration.

Though all adults should follow screening recommendations for HPV-related diseases, including cervical cancer, doing so is particularly important for those who are un- or under-vaccinated. The U.S. Preventive Services Task Force recommends that women ages 21 to 29 have a Pap smear every three years, to test for cervical abnormalities that may be indicative of cancer. Women ages 30 to 65 should have a Pap smear every three years, an HPV test every five years or a combination of the two every five years, the USPSTF says.

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Write to Jamie Ducharme at jamie.ducharme@time.com