HPV stands for human papillomavirus. You can get HPV by having sex or skin-to-skin genital contact with someone who has the virus. Infection with HPV is common, especially among young people. Most sexually active people in the United States will get HPV.^{footnote 1} But most people never know they have the virus, because it may not cause any symptoms.

There are more than 100 types of human papillomavirus. But only some types of HPV lead to cervical cancer or genital warts.

• Cervical cancerhappens when HPV causes abnormal cells in the cervix to grow out of control. HPV can stay in your body for a long time. It can take 10 years or more for a woman to get cancer from an HPV infection. Cervical cancer is one of the most common cancers in women.
• Genital warts(skin growths) may or may not cause symptoms. Even if you treat visible warts, or if the warts go away without treatment, the HPV infection can stay in the body’s cells. It’s possible to spread genital warts to a sex partner even if you can’t see the warts.

The HPV vaccines can help protect people from being infected with some of the most common types of the virus.

The HPV vaccine is a series of 2 or 3 shots given over 6 months. For the vaccine to work best, you need to get all the shots.

The vaccine doesn’t treat an HPV infection. But it may protect a person against types of the HPV virus other than the one causing the infection.

Health insurance may cover all or part of the cost of the vaccine. But if you don’t have health insurance, check with your local health department, clinic, or hospital about getting low-cost vaccine.

The HPV vaccine is recommended up to age 26.

The best time to get the vaccine is before you become sexually active. But it also protects against HPV after you’re sexually active (if you haven’t already been infected). When the vaccine is given before you become sexually active, it can prevent almost all infection by the types of HPV the vaccine guards against.^{footnote 2}

The vaccine can reduce your risk of getting genital warts or cervical cancer caused by some of the most common types of HPV infection. The HPV vaccine also helps protect against cancers of the anus, vagina, and vulva. Research is under way to see if the vaccine also can be used to prevent oral cancers.^{footnote 3}

The HPV vaccines were tested in thousands of people before being approved by the U.S. Food and Drug Administration (FDA), and there were no serious side effects. You can’t get HPV from the vaccine, and it doesn’t contain mercury.

The vaccine series helps protect against certain types of HPV for at least 5 years. Studies are under way to see how long the vaccine will last and if a booster shot is needed. A booster shot is another dose of the vaccine that is given after the first series of shots.

Some people may have mild side effects such as a low-grade fever and soreness in the arm where the shot was given. But neither lasts long. Your doctor may have you stay in the office for up to 15 minutes after the shot is given, to watch for any reactions.

Even though the HPV vaccine protects against most cervical cancers, women will need to get regular Pap tests to check for cervical cancer. This is because there are some types of HPV that the vaccine doesn’t prevent. Pap tests look for cells that may be, or can lead to, cervical cancer. If these cells are found early and treated, you may prevent cervical cancer. Experts recommend that women start having Pap tests at age 21.