What is HPV?
Human papillomaviruses are double-stranded DNA viruses found in the squamous epithelial cells on the surface of the skin and also the mucous membranes of the body.1 There are more than 200 known types of human papilloma viruses (HPVs) and most are not harmful.2 In the majority of cases, the human immune system clears HPV infections without symptoms or complications.3
More than 90 percent of those who become infected naturally clear the infection from the body within two years.4 Antibodies to the HPV type causing the infection remain in the body to help prevent future infections but the protection may not be life-long.5
Low Risk HPV Types - About 75 percent of HPVs have been associated with non-cancerous warts (papillomas) on the hands, chest, arms and feet, such as low-risk (wart-causing) HPV types 6 and 11.6 Low-risk HPV types associated with genital warts differ from high-risk HPV types that can be associated with development of cancer after years of chronic infection.7
High Risk HPV Types - About 40 HPV types have been found in the body’s mucosal membranes, such as the mucosal surfaces of the cervix, vagina, vulva, anus, penis, mouth and throat, including the most common high-risk HPV types 16 and 18. High-risk HPV types are associated with cancer of the cervix and five other genital and oral cancers affecting women and men if the HPV infection does not clear and becomes a chronic infection.8 High-risk HPV types currently include types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 69, 73 and 82.9
The National Cancer Institute states that “Virtually all cervical cancers are caused by HPV infections, with just two HPV types, 16 and 18, responsible for about 70 percent of all cases.”10 HPV type 16 causes 95 percent of all anal cancers, 50 percent of all vulvar cancers, 65 percent of all vaginal cancers, 35 percent of all penile cancers and more than half of the oropharyngeal cancers in the United States.11
IMPORTANT NOTE: NVIC encourages you to become fully informed about HPV and the HPV vaccine by reading all sections in the Table of Contents , which contain many links and resources such as the manufacturer product information inserts, and to speak with one or more trusted health care professionals before making a vaccination decision for yourself or your child. This information is for educational purposes only and is not intended as medical advice.
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1 CDC. Human Papillomavirus. Epidemiology and Prevention of Vaccine-Preventable Diseases (The Pink Book). 13th ed. 2015.
2 CDC. Surveillance Manual – Chapter 5: Human Papillomavirus (HPV) - Background. 6th Edition, 2013.
3 Ault KA, Epidemiology and Natural History of Human Papillomavirus Infections in the Female Genital Tract. Infect Dis Obstet Gynecol. 2006;2006(Suppl.):40470.
4 Cubie HA, Diseases associated with Human Papillomavirus infection. Virology. 2013 Oct;445(1-2):21-34.
5 Trottier H, Ferreira S. et al HPV infection and re-infection in adult women: the role of sexual activity and natural immunity. Cancer Res. 2010 Nov 1; 70(21): 8569–8577.
6 American Cancer Society. HPV Vaccines – What is HPV? Jun. 5, 2018
7 National Institutes of Health (NIH). HPV and Cancer. National Cancer Institute. Feb. 19, 2015.
8 CDC. Human Papillomavirus. Epidemiology and Prevention of Vaccine-Preventable Diseases (The Pink Book). 13th ed. 2015.
9 Schmitt M, Dondog B. et al. Abundance of Multiple High-Risk Human Papillomavirus (HPV) Infections Found in Cervical Cells Analyzed by Use of an Ultrasensitive HPV Genotyping Assay. J. Clin. Microbiol. Jan. 2010 vol. 48 no. 1 143-149
10 National Institutes of Health (NIH). HPV and Cancer. National Cancer Institute. Feb. 19, 2015.