For people aged 27 through 45, only those at risk for HPV should consider getting vaccinated, the agency noted.
The American Cancer Society (ACS) said that vaccinating young adults will have a small effect on the HPV epidemic and in reducing cancer rates, which is why they will keep pushing for kids to get vaccinated.
"Even with today's recommendation, the primary focus of efforts by the ACS and others will continue to be increasing vaccination in early adolescence," Debbie Saslow, managing director of HPV/GYN cancers at the American Cancer Society, said in a statement.
Evidence has shown that on-time vaccination will prevent about 90% of HPV cancers, Saslow said. Evidence has further shown that vaccination at older ages will have a limited effect on preventing cancer, she added.
"It will be important to determine which individuals would be most likely to benefit from vaccination at older ages, as well as how to best communicate with individuals inquiring about adult vaccination," Saslow said.
The vaccine is effective for those who have not been exposed to HPV, which is why preteens should get the vaccine before they become sexually active.
For many young adults who have not been exposed to HPV and have not been vaccinated, getting the vaccine will help protect them from cervical cancer, research shows.
HPV is a common sexually transmitted infection and can happen as soon as someone becomes sexually active.
Although most people who are infected don't know it because there are no symptoms, it can lead to cervical, anal, penile, vaginal, vulvar and oropharyngeal cancers, usually after many years.
Some adults exposed to HPV will develop natural immunity. Since it's hard to tell who may be immune, the CDC believes it's worthwhile for all young men and women to get vaccinated.
Getting the vaccine requires at least two shots spread over several months. Most insurance plans cover the cost of the vaccine, and Merck, who makes Gardasil, one of the two vaccines, has a patient assistance program to help cover the cost if insurance won't, according to the ACS.
The vaccine is both safe and effective, the CDC says.
Although not as many people have been vaccinated as the CDC would like, the vaccine has already markedly reduced HPV infections, according to the report by Dr. Elissa Meites, of the CDC's National Center for Immunization and Respiratory Diseases, and colleagues.
For example, the prevalence of infections in 2013 to 2016, compared with those before the vaccine was available, dropped from nearly 12% to less than 2% among girls aged 14 through 19, and from nearly 19% to just over 5% among women aged 20 through 24, the researchers reported.
Moreover, the vaccine has reduced HPV infection overall, as a herd effect has kicked in, the CDC report noted.
The recommendations were published Aug. 16 in the CDC's Morbidity and Mortality Weekly Report.