HPV Vaccine

What are human papillomaviruses?

Human papillomaviruses (HPVs) are a group of more than 200 related viruses. More than 40 HPV types can be easily spread through direct sexual contact, from the skin and mucous membranes of infected people to the skin and mucous membranes of their partners. They can be spread by vaginal, anal, and oral sex (1). Other HPV types are responsible for non-genital warts, which are not sexually transmitted.

Sexually transmitted HPV types fall into two categories:

  • Low-risk HPVs, which do not cause cancer but can cause skin warts on or around the genitals and anus. For example, HPV types 6 and 11 cause 90% of all genital warts. HPV types 6 and 11 also cause recurrent respiratory papillomatosis, a less common disease in which benign tumors grow in the air passages leading from the nose and mouth into the lungs.
  • High-risk HPVs, which can cause cancer. About a dozen high-risk HPV types have been identified. Two of these, HPV types 16 and 18, are responsible for most HPV-caused cancers (2, 3).

HPV infections are the most common sexually transmitted infections in the United States. About 14 million new genital HPV infections occur each year (4). In fact, the Centers for Disease Control and Prevention (CDC) estimates that more than 90% and 80%, respectively, of sexually active men and women will be infected with at least one type of HPV at some point in their lives (5). Around one-half of these infections are with a high-risk HPV type (6).

Most high-risk HPV infections occur without any symptoms, go away within 1 to 2 years, and do not cause cancer. Some HPV infections, however, can persist for many years. Persistent infections with high-risk HPV types can lead to cell changes that, if untreated, may progress to cancer.

Which cancers are caused by HPV?

High-risk HPVs cause several types of cancer.

  • Cervical cancer: Virtually all cases of cervical cancer are caused by HPV, and just two HPV types, 16 and 18, are responsible for about 70% of all cases (7, 8).
  • Anal cancer: About 95% of anal cancers are caused by HPV. Most of these are caused by HPV type 16.
  • Oropharyngeal cancers (cancers of the middle part of the throat, including the soft palate, the base of the tongue, and the tonsils): About 70% of oropharyngeal cancers are caused by HPV. In the United States, more than half of cancers diagnosed in the oropharynx are linked to HPV type 16 (9).
  • Rarer cancers: HPV causes about 65% of vaginal cancers, 50% of vulvar cancers, and 35% of penile cancers (10). Most of these are caused by HPV type 16.

High-risk HPV types cause approximately 5% of all cancers worldwide (11). In the United States, high-risk HPV types cause approximately 3% of all cancer cases among women and 2% of all cancer cases among men (12).

How is HPV transmitted?

Anyone who has ever been sexually active (that is, engaged in skin-to-skin sexual conduct, including vaginal, anal, or oral sex) can get HPV. HPV is easily passed between partners through sexual contact. HPV infections are more likely in those who have many sex partners or have sex with someone who has had many partners. Because the infection is so common, most people get HPV infections shortly after becoming sexually active for the first time (13, 14). A person who has had only one partner can get HPV.

Someone can have an HPV infection even if they have no symptoms and their only sexual contact with an HPV-infected person happened many years ago.

What is Pap and HPV testing?

HPV infections can be detected by testing a sample of cells to see if they contain viral DNA or RNA.

Several HPV tests are currently approved by the FDA for three cervical screening indications: for follow-up testing of women who seem to have abnormal Pap test results, for cervical cancer screening in combination with a Pap test among women over age 30, and for use alone as a first-line primary cervical cancer screening test for women ages 25 and older.

The most common HPV test detects DNA from several high-risk HPV types in a group, but it cannot identify the specific type(s) that are present. Other tests do tell in addition whether there is DNA or RNA from HPV types 16 and 18, the two types that cause most HPV-associated cancers. These tests can detect HPV infections before abnormal cell changes are evident, and before any treatment for cell changes is needed.

There are no FDA-approved tests to detect HPV infections in men. There are also no currently recommended screening methods similar to a Pap test for detecting cell changes caused by HPV infection in anal, vulvar, vaginal, penile, or oropharyngeal tissues. However, this is an area of ongoing research.

What are HPV Vaccines?

HPV vaccines are vaccines that protect against infection with HPV. The Food and Drug Administration (FDA) has approved three vaccines that prevent infection with disease-causing HPV types: Gardasil®, Gardasil® 9, and Cervarix®. All three vaccines prevent infection with HPV types 16 and 18, two high-risk HPVs that cause about 70% of cervical cancers and an even higher percentage of some of the other HPV-caused cancers (15, 16). Gardasil also prevents infection with HPV types 6 and 11, which cause 90% of genital warts (17). Gardasil 9 prevents infection with the same four HPV types plus five additional cancer-causing types (31, 33, 45, 52, and 58).

As of May 2017, Gardasil 9 is the only HPV vaccine available for use in the United States. Cervarix and Gardasil are still used in other countries.

Who should get HPV vaccination?

The CDC develops recommendations regarding all vaccination, including HPV vaccination. The current CDC recommendations for Gardasil 9 vaccination are as follows:

  • All children aged 11 or 12 years should get two HPV vaccine shots 6 to 12 months apart. If the two shots are given less than 5 months apart, a third shot will be needed. There could be future changes in recommendations on dosing.
  • HPV vaccine is recommended for young women through age 26, and young men through age 21.
  • Adolescents who get their first dose at age 15 or older need three doses of vaccine given over 6 months.
  • Persons who have completed a valid series with any HPV vaccine do not need any additional doses.

Additional guidance for specific populations, such as immunocompromised individuals (including those with HIV), men who have sex with men, and pregnant women, can be found on the CDC website.

How effective are HPV vaccines?

HPV vaccines are highly effective in preventing infection with the types of HPV they target when given before initial exposure to the virus—which means before individuals begin to engage in sexual activity.

In the trials that led to the approval of Gardasil and Cervarix, these vaccines were found to provide nearly 100% protection against persistent cervical infections with HPV types 16 and 18 and the cervical cell changes that these persistent infections can cause. Gardasil 9 is as effective as Gardasil for the prevention of diseases caused by the four shared HPV types (6, 11, 16, and 18), based on similar antibody responses in participants in clinical studies. The trials that led to approval of Gardasil 9 found it to be nearly 100% effective in preventing cervical, vulvar, and vaginal disease caused by the five additional HPV types (31, 33, 45, 52, and 58) that it targets (18).

How safe are the HPV vaccines?

Before any vaccine is licensed, the FDA must determine that it is both safe and effective. All three HPV vaccines have been tested in tens of thousands of people in the United States and many other countries. Thus far, no serious side effects have been shown to be caused by the vaccines. The most common problems have been brief soreness and other local symptoms at the injection site. These problems are similar to those commonly experienced with other vaccines. The vaccines have not been sufficiently tested during pregnancy and, therefore, should not be used by pregnant women.

To learn more about HPV, visit the CDC’s HPV website.

Content on this page was originally published by the National Cancer Institute on their HPV and Cancer and Human Papillomavirus (HPV) Vaccines pages and was adapted for our use.

References

  1. American Cancer Society. Cancer Facts & Figures 2014. Atlanta: American Cancer Society; 2014. Accessed February 25, 2014.
  2. Lowy DR, Schiller JT. Reducing HPV-associated cancer globally. Cancer Prevention Research (Philadelphia)2012;5(1):18-23. [PubMed Abstract]
  3. Centers for Disease Control and Prevention. Human papillomavirus-associated cancers—United States, 2004-2008. Morbidity and Mortality Weekly Report 2012; 61(15):258-261. [PubMed Abstract]
  4. Satterwhite CL, Torrone E, Meites E, et al. Sexually transmitted infections among US women and men: Prevalence and incidence estimates, 2008. Sexually Transmitted Diseases 2013; 40(3):187-193. [PubMed Abstract]
  5. Chesson HW, Dunne EF, Hariri S, Markowitz LE. The estimated lifetime probability of acquiring human papillomavirus in the United States. Sexually Transmitted Diseases 2014; 41(11):660-664. [PubMed Abstract]
  6. Hariri S, Unger ER, Sternberg M, et al. Prevalence of genital human papillomavirus among females in the United States, the National Health and Nutrition Examination Survey, 2003–2006. Journal of Infectious Diseases 2011; 204(4):566–573. [PubMed Abstract]
  7. Division of STD Prevention (1999). Prevention of genital HPV infection and sequelae: report of an external consultants' meeting. Atlanta, GA: Centers for Disease Control and Prevention. Retrieved December 27, 2011.
  8. Winer RL, Hughes JP, Feng Q, et al. Condom use and the risk of genital human papillomavirus infection in young women. New England Journal of Medicine 2006; 354(25):2645–2654. [PubMed Abstract]
  9. Chaturvedi AK, Engels EA, Pfeiffer RM, et al. Human papillomavirus and rising oropharyngeal cancer incidence in the United States. Journal of Clinical Oncology 2011; 29(32):4294–4301. [PubMed Abstract]
  10. Gillison ML, Chaturvedi AK, Lowy DR. HPV prophylactic vaccines and the potential prevention of noncervical cancers in both men and women. Cancer 2008; 113(10 Suppl):3036-3046. [PubMed Abstract]
  11. de Martel C, Ferlay J, Franceschi S, et al. Global burden of cancers attributable to infections in 2008: A review and synthetic analysis. Lancet Oncology 2012; 13(6):607-615. [PubMed Abstract]
  12. Jemal A, Simard EP, Dorell C, et al. Annual Report to the Nation on the Status of Cancer, 1975-2009, featuring the burden and trends in human papillomavirus (HPV)-associated cancers and HPV vaccination coverage levels. Journal of the National Cancer Institute 2013; 105(3):175-201. [PubMed Abstract]
  13. Collins S, Mazloomzadeh S, Winter H, et al. High incidence of cervical human papillomavirus infection in women during their first sexual relationship. British Journal of Obstetrics and Gynaecology 2002; 109(1):96-98. [PubMed Abstract]
  14. Winer RL, Feng Q, Hughes JP, et al. Risk of female human papillomavirus acquisition associated with first male sex partner. Journal of Infectious Diseases 2008; 197(2):279-282. [PubMed Abstract]
  15. Chaturvedi AK, Engels EA, Pfeiffer RM, et al. Human papillomavirus and rising oropharyngeal cancer incidence in the United States. Journal of Clinical Oncology 2011; 29(32):4294–4301. [PubMed Abstract]
  16. Gillison ML, Chaturvedi AK, Lowy DR. HPV prophylactic vaccines and the potential prevention of noncervical cancers in both men and women. Cancer 2008; 113(10 Suppl):3036-3046. [PubMed Abstract]
  17. Koutsky LA, Ault KA, Wheeler CM, et al. A controlled trial of a human papillomavirus type 16 vaccine. New England Journal of Medicine 2002; 347(21):1645-1651. [PubMed Abstract]
  18. Chatterjee A. The next generation of HPV vaccines: Nonavalent vaccine V503 on the horizon. Expert Review of Vaccines 2014; 13(11):1279-90. [PubMed Abstract]

Reprinted with permission from the National Cancer Institute.