HPV Vaccine Information for Clinicians

June 26, 2008


  • Virus-like Particles (VLPs) Assembled from the L1 Protein of Human Papillomavirus 16
    Virus-like Particles (VLPs) Assembled from the L1 Protein of Human Papillomavirus 16
    Approximately 20 million people are currently infected with genital human papillomavirus (HPV) in the United States (U.S.).1 As many as half of these infections are among adolescents and young adults, ages 15 through 24 years of age.2 HPV is so common that most sexually active adults become infected at some point in their lives.
  • Of the more than 40 types of HPV that infect human mucosal surfaces, most infections are asymptomatic and transient. However, certain oncogenic types can cause cervical cancer and other, less common anogenital cancers, including cancers of the anus, penis, and vulva. Other, non-oncogenic HPV types can cause genital warts and, rarely, respiratory tract warts in children.
  • Every year, about 12,000 women are diagnosed with cervical cancer, and almost 4,000 women die from this disease in the U.S.3 About 1% of sexually active men and women in the U.S. have genital warts at any given time.4
  • The quadrivalent human papillomavirus (HPV) vaccine, Gardasil®, is the first vaccine developed to protect against most cervical cancers and genital warts. The three-dose vaccine is routinely recommended for 11 and 12 year old girls. The vaccine series can be started at 9 years of age. Catch-up vaccination is recommended for 13 through 26 year old females who have not yet received or completed the vaccination series.5
  • This prophylactic vaccine works by preventing four HPV types: HPV 16 and 18, which cause 70% of cervical cancers, and HPV 6 and 11, which cause 90% of genital warts. The vaccine has no therapeutic effect on HPV-related disease, so it will not treat existing diseases or conditions caused by HPV.
  • The vaccine is made from non-infectious HPV-like particles (VLP). It does not contain thimerosal or mercury as a preservative.

HPV Vaccine Recommendations

  • The HPV vaccine is routinely recommended for 11 and 12 year-old girls. The vaccine series can be started at 9 years of age. Catch-up vaccination is recommended for 13 through 26 year-old females who have not yet received or completed the vaccine series.6
  • Ideally, females should be vaccinated before onset of sexual activity, when they may be exposed to HPV. However, sexually active females may also benefit from vaccination since few young women are infected with all four HPV types targeted by the vaccine (6, 11, 16, 18). Females who already have been infected with one or more HPV types would still get protection from the vaccine types they have not acquired. Currently, there is no test available for clinical use to determine whether a female has had any or all of the four HPV types targeted by the vaccine.

The HPV vaccine can be given to females who:

  • Are lactating.
  • Have minor acute illnesses, such as diarrhea or mild upper respiratory tract infections, with or without fever.
  • Have an equivocal or abnormal Pap test, a positive Hybrid Capture II® high risk test, or genital warts. However, women should be advised that data do not indicate that the vaccine will have any therapeutic effect on existing Pap test abnormalities, HPV infection or genital warts.
  • Are immunocompromised, either from disease or medication. However, the immune response to vaccination and vaccine efficacy might be less than in immunocompetent females.

The HPV vaccine should not be given to females who:

  • Are pregnant. Although the vaccine has not been causally associated with adverse pregnancy outcomes or adverse events to the developing fetus, data on vaccination in pregnancy are limited. Any exposure to vaccine in pregnancy should be reported to the vaccine pregnancy registry at (800) 986-8999.
  • Have a history of immediate hypersensitivity to yeast or to any vaccine component.
  • Have moderate or severe acute illnesses. In these cases, girls/women should wait until the illness improves before getting vaccinated.

HPV Vaccine Safety

  • The HPV vaccine has been studied in thousands of females (9 through 26 years of age) in many countries around the world, including the U.S. These studies found that the HPV vaccine was safe and caused no serious side effects. The most common adverse event was injection site pain. This reaction was common but mild.
  • Since vaccine licensure, there have been reports of syncope after vaccination. Syncope after any vaccination is more common in adolescents. Providers should consider a 15-minute waiting period for vaccine recipients following vaccination.
  • A detailed post-licensure safety monitoring plan, coordinated by the FDA and CDC, is in place. For more information about the Vaccine Adverse Events Reporting System (VAERS) visit

HPV Vaccine Efficacy and Antibody Response

  • The efficacy of this vaccine has mainly been studied in young women (16 through 26 years of age) who previously had not been exposed to the targeted HPV types. These clinical trials demonstrated nearly 100% vaccine efficacy in preventing cervical precancers, vulvar and vaginal precancers, and genital warts caused by the four vaccine types. In women already infected with a targeted HPV type, the vaccine did not prevent disease from that HPV type but did protect against other vaccine types.7 8 9
  • Immunogenicity studies i also have been conducted in girls, ages 9 to 15 years of age. Over 99% of vaccinated girls in these studies developed antibodies after vaccination. Titers were higher in these young girls, compared to older females in the efficacy trials (ages 16 through 26 years of age).10
  • While it is possible that vaccinating males with the quadrivalent vaccine may offer direct health benefits to males and indirect health benefits to females, there are currently no efficacy data available to support use of the HPV vaccine in males. Efficacy studies in males are ongoing. Information should be available within the next few years.

The vaccine offers a promising new approach to the prevention of HPV and associated conditions. However, it will not replace other prevention strategies since vaccines will not work for all HPV types.

i These studies provide support that vaccine efficacy data can be extrapolated from one population to another; in this case, from young adult women (ages 16 through 26 years of age) to younger girls (ages 9 through 15 years of age).

Duration of Vaccine Protection

  • Studies suggest that vaccine protection is long-lasting. Current studies (with about five years of follow-up data) indicate that the vaccine is effective for at least five years, with no evidence of waning immunity. This information will be updated as additional data regarding duration of immunity become available.

HPV Vaccine Administration

  • The vaccine should be delivered through a series of three intra-muscular injections over a six-month period. The second and third doses should be given two and six months after the first dose.
  • The vaccine can be administered at the same visit as other age-appropriate vaccines, such as Tdap, Td, MCV4, influenza, and hepatitis B vaccines.
  • Providers should consider a 15-minute waiting period for vaccine recipients following vaccination.

Cervical cancer screening recommendations have not changed for females who receive the HPV vaccine.

Covering the Cost of the Vaccine

  • Children age 18 and younger may be eligible to get vaccines, including the HPV vaccine, for free through the Vaccines for Children (VFC) program if they are: Medicaid eligible; uninsured; or American Indian or Alaska Native. Doctors can charge a fee to give each shot. However VFC vaccines cannot be denied to an eligible child if the family cannot afford the fee.
  • State and private programs offering free or low-cost vaccines may also be available for eligible persons. Contact your State Health Department to see if your state has such a program.

Vaccine Providers Should Notify Vaccinated Females That ...

  • It is important to get all three doses of the vaccine to get its full benefits.
  • Women will still need regular cervical cancer screening, beginning at age 21 or three years after initiating sexual activity, since the vaccine will not protect against all HPV types that cause cervical cancer.
  • They should continue to practice abstinence or protective sexual behaviors (i.e., condom use), since the vaccine will notprevent other sexually transmitted infections (STIs). Although condoms may not fully protect against HPV, they may lower one's chances of getting HPV and developing HPV-related diseases, when used all the time and the right way.11 Women can also lower their chances of getting HPV by being in a mutually faithful relationship with someone who has had no or few sex partners, or by limiting their number of sex partners.

CDC has developed several other resources, which vaccine providers may find useful for educating and counseling parents and young adult patients, including HPV brochures, HPV vaccine posters and flyers, HPV Vaccine Information for Young Women, and counseling messages for parents of potential vaccine recipients.

Other Vaccines in Development

  • A bivalent HPV vaccine is now being considered for licensure by the FDA. This vaccine would protect against the two types of HPV (16, 18) that cause 70% of cervical cancers. It would not protect against genital warts. Clinical trials in women ages 15 through 25 years of age have demonstrated high vaccine efficacy in preventing cervical precancers caused by HPV 16 and 18.12

Background: Cervical Cancer Prevention

Cervical cancer once claimed the lives of more American women than any other type of cancer. But over the last 40 years, widespread cervical cancer screening using the Pap test and treatment of pre-cancerous cervical abnormalities have resulted in a marked reduction in cervical cancer incidence and mortality in the U.S.13 New technologies, such as liquid-based cytology and an HPV DNA test, are now commercially available and licensed for use in women for cervical cancer screening and management, although they are not recommended by all professional associations.

Today, as many as 82% of women in the U.S. have been screened with a Pap test in the past three years.14 Despite this, U.S. screening programs are not reaching all women in the U.S. It is estimated that half of the women diagnosed with cervical cancer have never been screened for cervical cancer, and an additional 10% have not been screened in the previous 5 years.15 16 Cervical cancer disproportionately affects women of lower socioeconomic status, without regular access to health care, who are uninsured, and who are recent immigrants.17 18 These populations stand to benefit most from HPV vaccination.

Additional Information

See Also:


  1. Weinstock H, Berman S, Cates W, Jr. Sexually transmitted diseases among American youth: incidence and prevalence estimates, 2000. Perspect Sex Reprod Health. 2004; 36(1):6-10.
  2. Cates W, Jr. Estimates of the incidence and prevalence of sexually transmitted diseases in the United States. American Social Health Association Panel. Sex Transm Dis. 1999; 26(4):Suppl):S2-7.
  3. United States Cancer Statistics, National Program of Cancer Registries (NPCR). U.S. Cancers by Type.
  4. Koutsky LA, Galloway DA, Holmes KK. Epidemiology of genital human papillomavirus infection. Epidemiol Rev. 1988; 10:122-163.
  5. Markowitz LE, Dunne EF, Saraiya M, Lawson HW, Chesson H, Unger ER. Quadrivalent human papillomavirus vaccine: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 2007; 56: 1-24.
  6. Markowitz LE, Dunne EF, Saraiya M, Lawson HW, Chesson H, Unger ER. Quadrivalent human papillomavirus vaccine: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 2007; 56: 1-24.
  7. Garland SM, Hernandez-Avila M, Wheeler CM, Perez G, Harper DM, Leodolter S, et al. Females United to Unilaterally Reduce Endo/Ectocervical Disease (FUTURE) I Investigators. Quadrivalent vaccine against human papillomavirus to prevent anogenital diseases. N Engl J Med. 2007; 356(19):1928-43.
  8. The FUTURE II Study Group. Prophylactic efficacy of a quadrivalent human papillomavirus (HPV) vaccine in women with virological evidence of HPV infection. J Infect Dis. 2007; 196:1438-1446.
  9. FUTURE II Study Group. Quadrivalent vaccine against human papillomavirus to prevent high-grade cervical lesions. N Engl J Med. 2007; 356(19):1915-27.
  10. Block SL, Nolan T, Sattler C, Barr E, Giacoletti KE, Marchant CD, et al. Protocol 016 Study Group. Comparison of the immunogenicity and reactogenicity of a prophylactic quadrivalent human papillomavirus (types 6, 11, 16, and 18) L1 virus-like particle vaccine in male and female adolescents and young adult women. Pediatrics. 2006; 118(5):2135-45.
  11. Sexually Transmitted Diseases Treatment Guidelines, 2006. MMWR 2006; 55 [No. RR-11].
  12. Paavonen J, Jenkins D, Bosch FX, Naud P, Salmeron J, Wheeler CM et al. Efficacy of a prophylactic adjuvanted bivalent L1 virus-like-particle vaccine against infection with human papillomavirus types 16 and 18 in young women: an interim analysis of a phase III double-blind, randomised controlled trial. Lancet 2007;370(9596):1414.
  13. National Institutes of Health (NIH). NIH Consensus Statement: Cervical Cancer. 1996; 14:1-38.
  14. Swan J, Breen N, Coates RJ, Rimer BK, Lee NC. Progress in cancer screening practices in the United States: Results from the 2000 National Health Interview Survey. Cancer, 2003; 1528-1540
  15. Ho GY, Bierman R, Beardsley L, et al. Natural history of cervicovaginal papillomavirus infection as measured by repeated DNA testing in adolescent and young women. N Engl J Med. 1998; 338(7):423-428.
  16. Leyden WA, Manos MM, Geiger AM, Weinmann S, Mouchawar J, Bischoff K, et al.. Cervical cancer in women with comprehensive health care access: Attributable factors in the screening process. J Natl Cancer Inst. 2005;97(9):675-83.
  17. U.S. Cancer Statistics Working Group. United States Cancer Statistics: 1999-2002 Incidence and Mortality Web-based Report. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention and National Cancer Institute; 2005. Accessed December 6, 2005.
  18. Singh GK, Miller BA, Hankey BF, Edwards BK. Persistent area socioeconomic disparities in U.S. incidence of cervical cancer, mortality, stage, and survival, 1975-2000. Cancer, 2004;101(5):1051-7.

This article was provided by U.S. Centers for Disease Control and Prevention. Visit the CDC's website to find out more about their activities, publications and services.


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