Human papillomavirus (HPV) is an extremely common sexually transmitted infection of the genital areas, mouth, and throat of both females and males. There are over 100 types of HPV, some of which cause genital warts and various forms of cancer. According to the Centers for Disease Control and Prevention (CDC), about 79 million Americans are currently infected with HPV and about 14 million become newly infected each year, increasingly the likelihood that any sexually active person may contract the infection, even if they have only one partner. Most women and men will get at least one type of HPV infection during their lives, and most will never have any symptoms.


HPV, cancer, and precancer

The HPV vaccination prevents cancer.

Fifteen strains of HPV have been identified as risk factors for several cancers, including cancers of the cervix, vulva, vagina, anus, penis, mouth, and throat. While 90% of HPV infections heal within two years, some cases become chronic and develop into cancer, often over a period of 10 to 30 years. According to the CDC, HPV causes approximately 33,000 new cancers each year, about two-thirds of which occur in women, and one-third in men. These are in addition to nearly 360,000 cases of genital warts in the U.S. each year.

Each year, HPV is also implicated in millions of cases of cervical dysplasia—a precancerous condition in which abnormal cell growth occurs on the surface lining of the cervix. These diagnoses often require follow-up procedures such as cryotherapy or loop electrosurgical excision procedures (LEEP). In addition to the financial costs and anxiety induced by such procedures, they can also increase the risk of preterm labor.

VIDEO: Sarah Bradley, MD, and Bruce Campbell, MD, “The HPV Connection to Cancer,” Wisconsin HPV Vaccination Summit, June, 2016


HPV vaccination

In December of 2014, the U.S. Food and Drug Administration (FDA) approved Gardasil 9 (Human Papillomavirus 9-valent Vaccine, Recombinant) for the prevention of certain diseases caused by nine types of Human Papillomavirus (HPV). The new Gardasil 9 is approved for females ages 9 through 26 and males ages 9 through 15 and prevents cervical, vulvar, vaginal and anal cancers caused by HPV types 16, 18, 31, 33, 45, 52 and 58. Gardasil 9 also prevents genital warts caused by HPV types 6 and 11. Gardasil 9 adds protection against five additional HPV types—31, 33, 45, 52 and 58— which cause approximately 20 percent of cervical cancers and are not covered by the original Gardasil vaccine.

There are two other vaccines (the original Gardasil, and Cervarix) that protect against the most dangerous types of HPV infection. Each vaccine should be given as a three-shot series. The CDC Advisory Committee on Immunization Practices (ACIP) recommends that both girls and boys begin the series at age 11, though it is safe to begin as early as age 9. Catch up vaccination may occur up to age 26, though it is highly recommended that children be protected well before they become exposed to the disease through sexual activity.

The original Gardasil is a quadrivalent vaccine, meaning it protects against four types of HPV (types 6, 11, 16, and 18), while Cervix is a bivalent vaccine, meaning it protects against two types of HPV (types 16 and 18). Both vaccines have been found to be more than 92% effective at protecting against cervical precancer in females, while the quadrivalent vaccine has been found to be 100% effective at protecting against vulvar and vaginal precancer in women, 75% effective at protecting against anal precancer in men, and more than 89% effective at protecting against genital warts in men and women.


HPV vaccine safety

As with all approved vaccines, CDC and the Food and Drug Administration (FDA) closely monitor the safety of HPV vaccines following licensure. Clinical trials and post-licensure monitoring data show that both vaccines are safe. Below are summary findings of two systems that the CDC and FDA use to monitor the safety of vaccines.

  • The Vaccine Adverse Event Reporting System (VAERS): Between 2006 and 2011, women and girls received approximately 67 million doses of HPV vaccines. VAERS received approximately 25,000 reports of adverse events, 92% of which were classified as “non-serious,” including injection-site reactions, dizziness, fainting, nausea, and headache.

  • The Vaccine Safety Datalink (VSD): Following more than 600,000 doses of Gardasil, adverse events in the HPV vaccinated population were compared to adolescents who received vaccines other than HPV. Incidents of serious complications like Guillain–Barré syndrome (GBS), stroke, venous thromboembolism (VTE), appendicitis, seizures, syncope (fainting), allergic reactions, and a potentially life-threatening allergic reaction called anaphylaxis were no more common among those who received the HPV vaccination than among the comparison groups.

In 2011, the Institute of Medicine (IOM) produced a report, Adverse Effects of Vaccines:Evidence and Causality, which concluded that some people who receive injected vaccines, including HPV vaccine, experience fainting. The report also affirmed that anaphylaxis can occur in people with severe allergic reactions to any component of any vaccine, including HPV. People with severe allergic reactions to any component of the HPV vaccine should not receive it.

UW Health Immunization Task Force/HPV Work Group Quality Improvement Initiative

As part of our efforts to increase HPV vaccination rates in the state of Wisconsin, Sarah Bradley, MD of the UW Department of Obstetrics and Gynecology and Lindsay Geier, MD of the UW Department of Pediatrics conducted educational sessions on the HPV vaccination to providers and staff at 15 UW Health clinics between May and October, 2014. The sessions included facts about HPV, HPV-related cancers, and the HPV vaccine, as well as data regarding each individual clinic's HPV vaccination rates, and comparisons with system, state, and national rates. Drs. Bradley and Geier also addressed patient, provider, and system barriers to completion of the three-shot HPV vaccination series and lead discussions on overcoming these barriers. Clinic data will continue to be tracked in order to gauge the success of these educational efforts.


More information about HPV and HPV vaccination

Sarah Bradley, MD, assistant professor of Obstetrics and Gynecology and physician champion of the department's HPV vaccination initiatives has been invited to speak about HPV and HPV vaccination by the Wisconsin Primary Health Care Association, Public Health of Madison and Dane County, Mercy Health Care System, and the Wisconsin HPV Vaccine Summit. If you are interested in having Dr. Bradley speak to your group, please contact her at 608-828-7610 or sarah.bradley@uwmf.wisc.edu.

Wisconsin Comprehensive Cancer Control Program (WCCCP) – Protecting Wisconsin youth from HPV-related cancers

WCCCP – HPV vaccine: A tool for cancer prevention

Centers for Disease Control and Prevention – HPV prevention

The President's Cancer Panel – Accelerating HPV vaccine uptake: Urgency for action to prevent cancer

FAQ: HPV vaccine safety – James H. Conway, MD, Wisconsin AAP Infectious Disease and Immunizations Chair

American Academy of Pediatrics – HPV resources for providers


Selected research about HPV and HPV vaccination

Human papillomavirus: Recommendations of the Advisory Committee on Immunization Practices (ACIP) (Markowitz et al., 2014)

Barriers to human papillomavirus vaccination among US adolescents: A systematic review of the literature (Homan et al., 2014)

Long-term study of a quadrivalent human papillomavirus vaccine (Ferris et al., 2014)

Human papillomavirus: What every provider should know (Erickson et al., 2013)

Safety of quadrivalent human papillomavirus vaccine administered routinely to females (Klein et al., 2012)

Efficacy of quadrivalent HPV vaccine against HPV infection and disease in males (Giuliano et al., 2011)

Physician Champion

Sarah Bradley, MD - UW Obstetrics and Gynecology, Madison WI
Sarah L. Bradley, MD
Clinical Assistant Professor, General Obstetrics and Gynecology

Obstetrics and Gynecology Clinic
Tel: 608-828-7610
7102 Mineral Point Rd
Madison, WI 53717