Updated on April 17, 2024.
Human papillomavirus (HPV) is a sexually transmitted virus that can cause genital warts and cancers of the reproductive system, particularly cancer of the cervix (the lower part of the uterus).
More than 42 million people in the United States are currently infected with types of HPV that can cause disease, according to the Centers for Disease Control and Prevention (CDC). In fact, almost all people who are sexually active are exposed to it at some point in their lives, says Michael Liao, MD, an OBGYN with Summerville Women’s Care in South Carolina.
The HPV vaccine can prevent most of these cancers from developing. In fact, the CDC estimates that about 33,700 of the 36,500 cases of cancer that are associated with HPV infection and that occur every year in the United States can be prevented with the vaccine.
Although most HPV infections never cause any symptoms or serious problems and go away on their own within two years, it’s important to take precautions with regular screenings and vaccinations. They could save your life—or the life of someone you know.
What is HPV and how does it spread?
HPV is the most common sexually transmitted infection in the United States. It is actually a collection of more than 200 associated viruses (also called strains), 13 of which can cause cancer. Some strains of HPV cause warts or skin growths and some may never lead to any health issues at all.
“Some of the strains are little nuisance types of viruses that don't do much and some of them are cosmetically distressing,” says Dr. Liao. “But more significantly, certain strains are what we call high-risk in terms of how they damage DNA [genetic material] and make the cells grow abnormally, and they can contribute to cancer.”
A total of 40 strains are spread through direct sexual contact—the intimate skin-to-skin interaction that comes from vaginal, anal, or oral sex. If you have sex with someone who has HPV, you can get it even if the person you have sex with doesn’t have any symptoms. Other strains, such as those that cause warts on areas like the hands and feet, can be spread by touching surfaces.
What is the HPV vaccine?
The vaccines that protect against HPV encourage the body to make antibodies, which are proteins used by the immune system to fight viruses. If these antibodies are ever exposed to HPV, they attach to the virus and prevent it from invading the body’s cells.
There are three different vaccines for protection against infections associated with HPV that are approved by the U.S. Food and Drug Administration (FDA): Gardasil, Gardasil 9, and Cervarix.
All of the vaccines protect to varying degrees against the HPV types associated with cervical cancer and other cancers, including cancer of the anus (opening where bowel movements exit the body), oropharynx (back of the throat), vulva (outside part of the female reproductive organs), vagina (passageway between the cervix and outside the body), and penis (outside part of the male reproducitve organs). Only Gardasil 9 is now used in the U.S., however, because it provides the broadest protection against HPV strains that can cause cancer. The other two vaccines are still used in other countries around the world.
Who should get vaccinated—and when?
All children should receive the two-dose HPV vaccine between the ages of 11 and 12, although it may be given as early as age 9. If a teenager hasn’t gotten the vaccine yet, tthey should see a healthcare provider (HCP) and get it as soon as possible. After age 14, three shots are needed instead of two.
“It’s important for young people to remember that even if they missed their early dose of the vaccine, they should still consider getting vaccinated because there are lots of different strains out there,” says Liao. “While the vaccine won't necessarily go back and reverse the course of the prior exposure, it can help prevent future exposures from other strains that they haven't been exposed to yet.”
People who have not previously been vaccinated can also receive the vaccine until age 26, but being vaccinated at older ages is less effective for lowering cancer risk. In special circumstances, an HCP may recommend that someone receive the vaccine up until age 45.
Regular screenings are also important
Not all cancers associated with HPV have screening options available. These include anal, penile, and oropharyngeal cancers.
But there is one very important screening method for people assigned female at birth: In addition to getting the HPV vaccine, it’s vital to get regular cervical cancer screenings in the form of Pap smears (when an HCP uses a small brush to gently collect cells from the surface of the cervix to check for irregular cells that may indicate cancer), as well as a specific HPV test (which checks for HPV in cells from the cervix). The American College of Obstetricians and Gynecologists’ guidelines are as follows:
- Ages 21 to 29: Pap smear every three years
- Ages 30 to 65: Pap smear alone every three years, or specific HPV test every five years, or Pap smear plus HPV testing every five years
Sometimes, your OBGYN may suggest an HPV test as a follow-up if your Pap smear comes back abnormal, says Liao.
When it comes to screenings and testing, it’s important to talk with your HCP. How often you need a Pap smear depends on your age and health history. It’s also important for everyone to have routine checkups with their primary care physician.
If you get the HPV vaccine, it’s likely you’ll be protected against most cancers and other diseases HPV can cause, such as genital warts. However, if you notice any symptoms that are not usual for you, see your HCP.
People who have irregular vaginal bleeding such as bleeding after sex or after menopause (not having a period for 12 months in a row), discharge between periods that is not typical for them, or pain while having sex should see their HCP. Although these symptoms can be signs of many other conditions, they could be signs of cervical cancer or precancers.
The most important thing you can do to protect yourself against HPV and the conditions related to it is to be proactive. The HPV vaccine is extremely effective when taken well before someone becomes sexually active, so it’s best to get vaccinated during the preteenage years or as a young adult. Continuing regular screenings is important, too.
“If you’re going to your primary care physician and OBGYN regularly, your providers should be able to detect any problems before they become too significant,” says Liao.
