The HPV "ABC"
What is HPV?
HPV is short for human papillomavirus and is a group of more than 150 related viruses. Each HPV virus in this large group is given a number which is called its HPV type. HPV is named for the warts (papillomas) some HPV types can cause. Some other HPV types can lead to cancer, especially cervical cancer. There are more than 40 HPV types that can infect the genital areas of males and females. But there are vaccines that can prevent infection with the most common types of HPV.
How do people get HPV?
HPV is transmitted through intimate skin-to-skin contact. You can get HPV by having vaginal, anal, or oral sex with someone who has the virus. It is most commonly spread during vaginal or anal sex. HPV is the most common sexually transmitted infection (STI). Anyone who is sexually active can get HPV, even if you have had sex with only one person. HPV is so common that nearly all sexually active men and women get it at some point in their lives. HPV can be passed even when an infected person has no signs or symptoms. You can develop symptoms years after you have sex with someone who is infected, making it hard to know when you first became infected.
HPV vaccines are given as a series of three shots over 6 months to protect against HPV infection and the health problems that HPV infection can cause. There are three HPV vaccines (Cervarix, Gardasil, and Gardasil 9). Girls and young women should get any of these HPV vaccines to prevent cervical cancer.
Two of the HPV vaccines (Gardasil and Gardasil 9) also protect against genital warts and anal cancer in both females and males. Boys should get one of these HPV vaccines to prevent anal cancer and genital warts. Girls can get either of these vaccines to prevent cervical cancer, vulvar cancer, vaginal cancer, anal cancer and genital warts.
HPV vaccines offer the best protection to girls and boys who receive all three vaccine doses and have time to develop an immune response before being sexually active with another person. That's why HPV vaccination is recommended for preteen girls and boys at age 11 or 12 years.
Who else should get the HPV vaccine?
All kids who are 11 or 12 years old should get the three-dose series of HPV vaccine to protect against HPV. Teen boys and girls who did not start or finish the HPV vaccine series when they were younger should get it now. Young women can get HPV vaccine through age 26, and young men can get vaccinated through age 21. The vaccine is also recommended for any man who has sex with men through age 26, and for men with compromised immune systems (including HIV) through age 26, if they did not get HPV vaccine when they were younger.
How can people prevent HPV?
There are several ways that people can lower their chances of getting HPV:
Vaccines can protect males and females against some of the most common types of HPV. HPV vaccines are safe and effective. They are given in three doses over six months. HPV vaccines are most effective when given at 11 or 12 years old.
- Girls and women: Two vaccines (Cervarix and Gardasil) are available to protect females against the types of HPV that cause most cervical cancers. One of these vaccines (Gardasil) also protects against most genital warts. This vaccine has also been shown to protect against anal, vaginal and vulvar cancers. Both vaccines are recommended for 11 or 12 year-old girls, and for females through 26 years of age, who did not get any or all of the doses when they were younger.
- Boys and men: One vaccine (Gardasil) protects males against most genital warts and anal cancers. This vaccine is recommended for boys aged 11 or 12 years, and for males aged through 21 years of age, who did not get any or all doses when they were younger. The vaccine is also recommended for gay and bisexual young men (or any young man who has sex with men) and also for young men with compromised immune systems (including HIV) through age 26, if they did not get HPV vaccine when they were younger.
For those who are sexually active, condoms may lower the risk of HPV infection. To be most effective, they should be used with every sex act, from start to finish. Condoms may also lower the risk of developing HPV-related diseases, such as genital warts and cervical cancer. But HPV can infect areas that are not covered by a condom - so condoms may not fully protect against HPV.
People can also lower their chances of getting HPV by being in a faithful relationship with one partner; limiting their number of sex partners; and being with a partner who has had no or few prior sex partners. But even people with only one lifetime sex partner can get HPV. And it may not be possible to determine if a partner who has been sexually active in the past is currently infected. Not having sex is the only sure way to avoid HPV.
How can people prevent HPV-related diseases?
There are ways to prevent the possible health effects of HPV, including two common problems: genital warts and cervical cancer.
- Preventing Genital Warts: One vaccine (Gardasil) protects against most genital warts in men and women.
- Preventing Cervical Cancer: Two vaccines (Cervarix and Gardasil) protect against most cervical cancers in women. Cervical cancer can also be prevented with routine cervical cancer screening (Pap test) and follow-up of abnormal results. The Pap test can find abnormal cells on the cervix so that they can be removed before cancer develops. Abnormal cells often become normal over time, but can sometimes turn into cancer. These cells can usually be treated, depending on their severity and on the woman’s age, past medical history, and other test results. An HPV DNA test, which can find certain HPV types on a woman's cervix, may also be used with a Pap test in certain cases (called co-testing). Even women who were vaccinated when they were younger need regular cervical cancer screening because the vaccines do not protect against all cervical cancers.
- Preventing Anal and Penile Cancers: One vaccine (Gardasil) protects against most anal cancers. There is no routinely recommended screening test for anal or penile cancer because more information is still needed to find out if those tests are effective. There are no data on efficacy of the vaccine to prevent cancers of the penis, but most HPV-related cancers of the penis are caused by the HPV types prevented by the vaccines. Both vaccines are likely to prevent HPV-16- and HPV-18-related cancers of the anus and penis; systems that monitor cancer rates through time will help clarify the impact of vaccine on these cancers.
- Preventing Cancers of the Oropharynx (also called oropharyngeal cancer; cancers of the back of the throat, including the base of the tongue and tonsils): There is no approved test to find early signs of oropharyngeal cancer because more information is still needed to find out if those tests are effective. There are no data on efficacy of the vaccine to prevent cancers of the oropharynx, but most HPV-associated cancers of the oropharynx are caused by the HPV types prevented by the vaccines. Smoking is also a risk factor for cancers of the oropharynx, so not smoking or quitting can help reduce your risk.
- Preventing Juvenile-Onset Recurrent Respiratory Papillomatosis (JORRP): Cesarean ("C-section") delivery is not recommended for women with genital warts to prevent JORRP in their babies. This is because it is not clear that cesarean delivery prevents JORRP in infants and children. There are no data on efficacy of the vaccine to prevent recurrent respiratory papillomatosis but most cases are caused by the HPV types prevented by the one of the vaccines (Gardasil). Gardasil is likely to prevent HPV-6 and -11 related RRP.
Although there is no routine screening test for HPV-associated diseases other than cervical cancer, you should visit your doctor regularly for checkups.
Symptoms and Health Consequences
What are the signs, symptoms and health consequences of HPV?
In most cases, HPV goes away on its own and does not cause any health problems. But when HPV does not go away, it can cause health problems like genital warts and cancer.
Genital warts usually appear as a small bump or groups of bumps in the genital area. They can be small or large, raised or flat, or shaped like a cauliflower. A healthcare provider can usually diagnose warts by looking at the genital area.
Cervical cancer usually does not have symptoms until it is quite advanced, very serious and hard to treat. For this reason, it is important for women to get regular screening for cervical cancer. Screening tests can find early signs of disease so that problems can be treated early, before they ever turn into cancer.
Other HPV-related cancers might not have signs or symptoms until they are advanced and hard to treat. These include cancers of the vulva, vagina, penis, anus, and oropharynx (cancers of the back of the throat, including the base of the tongue and tonsils).
Does HPV cause cancer?
HPV can cause cervical and other cancers including cancer of the vulva, vagina, penis, or anus. It can also cause cancer in the back of the throat, including the base of the tongue and tonsils (called oropharyngeal cancer).
Cancer often takes years, even decades, to develop after a person gets HPV. The types of HPV that can cause genital warts are not the same as the types of HPV that can cause cancers.
There is no way to know which people who have HPV will develop cancer or other health problems. People with weak immune systems (including individuals with HIV/AIDS) may be less able to fight off HPV and more likely to develop health problems from it.
HPV Vaccine Safety
The human papillomavirus (HPV) vaccines are safe, effective, and offer long-lasting protection against cancers caused by HPV.
Each HPV vaccine—Gardasil® 9, Gardasil®, and Cervarix®—went through years of extensive safety testing before they were licensed by the U.S. Food and Drug Administration (FDA). Gardasil® 9 was studied in clinical trials with more than 15,000 females and males; Gardasil® was studied in clinical trials with more than 29,000 females and males, and Cervarix® was studied in trials with more than 30,000 females.
Research from before and after the vaccines were licensed show that HPV vaccines are safe. As with all approved vaccines, CDC and the FDA closely monitor the safety of HPV vaccines after they are licensed. Any problems detected with these vaccines will be reported to health officials, health care providers, and the public.
Like any vaccine or medicine, HPV vaccines can cause side effects. The most common side effects are pain, redness, or swelling in the arm where the shot was given; dizziness, fainting, nausea, and headache. HPV vaccination is typically not associated with any serious side effects. The benefits of HPV vaccination far outweigh any potential risk of side effects.
Is there a treatment for HPV or related problems?
There is no treatment for the virus itself, but there are treatments for the problems that HPV can cause:
- Visible genital warts may remain the same, grow more numerous, or go away on their own. They can be removed by the patient with medications. They can also be treated by a health care provider. Some people choose not to treat warts. No one treatment is better than another.
- Abnormal cervical cells (found on a Pap test) often become normal over time, but they can sometimes turn into cancer. If they remain abnormal, these cells can usually be treated to prevent cervical cancer from developing. This may depend on the severity of the cell changes, the woman’s age and past medical history, and other test results. It is critical to follow up with testing and treatment, as recommended by a doctor.
- Cervical cancer is most treatable when it is diagnosed and treated early. Problems found can usually be treated, depending on their severity and on the woman’s age, past medical history, and other test results. Most women who get routine cervical cancer screening and follow up as told by their provider can find problems before cancer even develops. Prevention is always better than treatment.
- Other HPV cancers are also more treatable when diagnosed and treated early. Although there is no routine screening test for these cancers, you should visit your doctor regularly for checkups.
- Recurrent Respiratory Papillomatosis (RRP), a rare condition in which warts grow in the throat, can be treated with surgery or medicines. It can sometimes take many treatments or surgeries over a period of years.
HPV and Cancer
Several types of cancer are associated with HPV:
- Cervical cancer: The most common HPV cancer. Almost all cervical cancer is caused by HPV.
- Vulvar cancer: About 69% are linked to HPV.
- Vaginal cancer: About 75% are linked to HPV.
- Penile cancer: About 63% are linked to HPV.
- Anal cancer: About 91% are linked to HPV.
- Oropharyngeal cancers (cancers of the back of the throat, including the base of the tongue and tonsils): About 72% are linked to HPV. [Note: Many of these cancers may be related to tobacco and alcohol use]
Most of the time, HPV goes away by itself within two years and does not cause health problems. It is thought that the immune system fights off HPV naturally. It is only when certain types of HPV do not go away over years that it can cause these cancers. It is not known why HPV goes away in most, but not all cases. There is no way to know which people will go on to develop cancer or other health problems.