Think that the human papillomavirus (HPV) vaccine is only good for your kids? Think again! The same vaccine that tweens routinely receive at well-child visits to lower their risk of certain cancers is now available to people as old as 45.

The Centers for Disease Control and Prevention (CDC) recently expanded its recommendations for the HPV vaccine because research has shown that it can help prevent cancer in more people.

Many people will get HPV, the most common sexually transmitted disease. In this way, HPV is like the common cold. It often doesn't cause symptoms to let you know that you've been infected. Some HPV infections are harmless, while others can cause genital warts or cancer. The vaccine protects against the most common of these harmful types.

"It's primarily a cervical cancer vaccine, but it also can prevent other HPV-related cancers—whether it's anal cancer, penile cancer, vaginal cancer or oropharyngeal cancers that happen in the throat," says Dr. Kenneth H. Kim, director of Gynecologic Oncology at Cedars-Sinai. "There are no other cancers that we can prevent like this with a shot."

The vaccine is most protective if you haven't been exposed to certain HPV types. It's recommended for 11- and 12-year-olds because most adolescents at that age haven't become sexually active.

Previously, the HPV vaccine was recommended for females through age 26 and males through age 21 who weren't vaccinated on schedule. Now, the CDC recommends that all adults through age 26 should get vaccinated if they missed it during the middle-school years, and adults aged 27 through 45 should ask their doctors if the HPV vaccine is right for them, even if they're sexually active.

"People who have been exposed to HPV might have only been exposed to one type or another, but maybe not some of the other high-risk subtypes," Dr. Kim says. "There is likely some benefit in preventing cervical cancer or other cancers that would be a result from high-risk HPV subtypes that they may not have been exposed to."

Here's why you should consider the HPV vaccine:

Up to 80 million Americans may have HPV at any given moment. People aged 27 to 45 still become infected, especially those with new sexual partners.

"Studies have shown that the prevalence of HPV in those age groups—over 25—are roughly 20% to 30%," Dr. Kim says. "There's a slight decline as the decades go by, but it's still a pretty large number."

When the HPV vaccine was approved in 2006, it was recommended for females up to age 26 only. In 2011, the recommendation expanded to males up to age 21.

Then in 2018, the U.S. Food and Drug Administration announced that it expanded approved usage of the HPV vaccine to include males and females up to age 45. In 2019, the CDC recommended the vaccine for all males and females up to age 26, and they also advised that people between 27 and 45 should ask their doctors about the vaccine because it might be beneficial.

If you're between 27 and 45, you may not have had the opportunity to get the vaccine as an adolescent, especially if you're male or transgender. Talk to your doctor if you didn't get vaccinated as a teen.

"It's definitely something to consider. And for younger transgender individuals in particular, that's a very important discussion to have with their physician," Dr. Kim says. "If we're going to really reach herd immunity to prevent these cancers, we've got to vaccinate the whole population."

In recent years, oral cancer has outpaced cervical cancer as the most commonly diagnosed cancer caused by HPV. If you haven't been exposed to the HPV types that cause these and other cancers, getting vaccinated may help lower your risk as you get older.

"Some of those cancers are cancers that happen in an older age group," Dr. Kim says. "This is an extremely safe and effective vaccine, and there are very few contraindications to getting it."

If you're between 27 and 45, ask your doctor if you should get the HPV vaccine—based on your sexual history and relationship status. If you foresee having new sexual partners, the vaccination may protect you, but it isn't right for everyone.

"People who are in a monogamous relationship of some sort and those who are otherwise at very low risk of developing cervical cancer or any of these cancers may not need it," Dr. Kim says. "This is something to talk to your physician about."