The HPV Vaccine

Megan Cole, Diana Zuckerman, PhD, Brandel France de Bravo, MPH, and Janet A. Phoenix, MD, MPH, Cindy Min, MPH, National Center for Health Research

What is a HPV Vaccine?

The human papillomavirus virus, also known as HPV, is the most common sexually transmitted infection in the world. It can cause various different type of cancer including cervical, vaginal, anal, penile, and more. For more information about the HPV, you can read this(link) article.[1]

The first vaccine against harmful strains of HPV was the Quadrivalent Human Papillomavirus vaccine (Gardasil). It was approved by the Food and Drug Administration (FDA) in June 2006 and received a lot of publicity as “the first cancer vaccine.” Gardasil was approved in children and adults, ages 9 through 26. It protects against two types (16 and 18) of HPV infection that are responsible for 70% of cervical cancer cases and two other types (6 and 11) of HPV infection that are responsible for 90% of genital warts cases. In 2014, the FDA replaced Gardasil with Gardasil 9, which added five additional types of HPV (31, 33, 45, 52, and 58).[2] In 2018, FDA expanded the approval of the vaccine to women and men aged 27 through 45 years old.[3] Since not all types of HPV are covered by the vaccine, girls and women who are vaccinated with Gardasil will still need regular Pap smears and/or HPV testing to detect cervical cancer in its early stages when treatment is most effective. In 2008, Gardasil was also approved to protect against vaginal and vulvar cancers.[4]

The Gardasil vaccine is administered in three doses over a six-month period. The home page of its Gardasil website ( that: “The duration of protection of Gardasil has not been established.”

In a 2020 study published in The Lancet, young women (16-23 years) who received three full doses of the HPV vaccine were followed for 10 years in order to assess the effectiveness of the vaccine. The first two doses of the vaccine were given 1 month apart, and the last dose was given 6 months after the first dose was administered. At the 10 year follow-up, no cases of cervical cancer  were observed in any women.   There were sustained antibody responses for up to 14 years post-vaccination. This means that the HPV vaccine produced adequate levels of antibodies to prevent the virus for over 14 years. No additional vaccination was warranted since there was no evidence that the vaccination lost effectiveness.[5]

A second HPV vaccine, known as Cervarix, was approved by the FDA in October 2009. It is produced by GlaxoSmithKline and became available in May 2010. Cervarix was approved for use in girls ages 10 to 25, and like Gardasil, is given as a three dose series over six months. Unlike Gardasil, Cervarix only protects against two HPV strains-types 16 and 18, which are the leading causes of cervical cancer. Luncertain. In 2014, GlaxoSmithKline decided to discontinue Cervarix in the US market due to low demand, but it is still sold in Europe.[6]

How Effective is the Vaccine?

Efficacy of Gardasil vaccine has been reported ranging from 85-96% against HPV virus strain 16 and 18. Additionally, a 2019 meta-analysis of HPV vaccination programs conducted in 14 different countries showed strong effectiveness of the HPV vaccine. This report stated up to 8 years after the program was launched there was a 83% decrease in HPV infection (16 and 18) among girls aged 15-19 years and a 66% decrease among women aged 20-24 years. Cervarix, even though discontinued in the United States, showed almost 91-94% effectiveness in preventing HPV infection (16 and 18) in women.[7]

Are these Vaccines Safe?

As with any vaccine, it is important to consider the vaccine’s safety and potential side effects. Clinical trials were performed to demonstrate safety before the vaccines were licensed.[8]

Safety information for Gardasil and Gardasil 9 is available through the Vaccine Adverse Event Reporting System (VAERS). In 2019, CDC analyzed VAERS for adverse events relating to the HPV vaccine. There were 7,244 reports submitted between 2014 to 2017 to VAERS. The report showed 97% of the adverse events were classified as non-serious, which includes fainting, pain and swelling at the injection site, headache, nausea, and fever.  Around 3% of the reports were considered serious adverse events. Serious adverse events included hospitalization, prolongation of existing hospitalization, permanent disability, life-threatening illness, congenital anomaly or birth defect, or death.[9]

There has been some concern about a link between Gardasil and a rare nervous system disorder known as Guillain-Barré syndrome (GBS). A 2017 study examined diagnosis for Guillain Barré Syndrome (GBS) within 6 weeks of patients receiving the quadrivalent HPV vaccine. Out of 2,773,185 doses of the vaccine, there was only 1 confirmed case of GBS. The study concluded there was no evidence of an increased risk of GBS following the vaccine.[10] Similar results were seen in a study published in England in 2016, which also found no increase in the incidence of GBS after vaccine administration. [11]

National Recommendations

In 2019, Committee on Immunization Practices (ACIP) recommended children and adults aged 9 through 26 to receive three doses of HPV vaccine. The vaccination can be given as early as 9 years old, but is recommended to be given at age 11 or 12. For adults aged 26 years or older, ACIP recommended to make a shared clinical decision with a physician before receiving the HPV vaccine. For individuals who are pregnant, it is best to delay the vaccination until after pregnancy although pregnancy testing before vaccination is not necessary. Currently, the vaccine is not approved for adults aged 45 years or older.[23]

Who should get the HPV vaccine? Who should not?

The data that Merck presented to the FDA in 2006 indicated that Gardasil would not be effective against strains of HPV that the women were currently infected with at the time of vaccination. This finding has often been misunderstood. What it means is that the vaccine will not treat existing infections. However, data show that having a previous HPV infection that has cleared by the time you get the vaccine will not interfere with the vaccine’s effectiveness. But, if you have an ACTIVE infection that has not cleared, the vaccine will not be as effective against that type of HPV in the future.

At what age is it most effective?

Because HPV exposure may occur even in the first 10 years of life through non-sexual skin-to-skin contact, or while being born, there is no age at which the vaccine will always be effective for everyone. According to the Centers for Disease Control (CDC), “the best way a person can be sure to get the most benefit from HPV vaccination is to complete all three doses before beginning sexual activity.”[13]

While researchers still do not understand or agree on the level of antibody titers, amount of antibodies present in the body, necessary to have protection from HPV, there are data to indicate that most teenagers and women who are vaccinated after being previously exposed to HPV have even more antibodies than those who are vaccinated before they become sexually active.[14]

I did not get my vaccine when I was younger. Is the vaccine recommended for individuals over 26?

In 2018, the FDA approved Gardasil to include women and men 27 through 45. This was based on a study with 3,200 women 27 through 45 years of age, who were followed for an average of 3.5 years. In this study, Gardasil was 88% effective in preventing genital warts, persistent infection, vulvar and vaginal precancerous lesions, cervical precancerous lesions, and cervical cancer.[15] Currently, the CDC does not recommend HPV vaccination for all adults older than 26 years. Instead, a patient over age 26 should talk with their doctor in order to decide whether to get the vaccine. To obtain more information on what factors should be considered, you can read this (link) guide by the CDC.[16]

How do I get an HPV Vaccine?

The retail price of the vaccine is about $227 per dose, but most large insurers cover the costs of the vaccine, which may be administered by your doctor.[17]

Gardasil vaccine is covered by most insurance plans since it counts as preventive care.[18] The CDC Committee has also recommended that the HPV vaccine be included in the Vaccines for Children (VFC) Program, the federal program which provides free vaccinations to children 18 years of age and under who are uninsured, on Medicaid, protected by the Indian Health Services Act, or underinsured.[19] Children enrolled in the VFC program receive the vaccine free of charge.

Additional details regarding the Vaccines for Children Program, including what it is, who is eligible, what it covers, and how to enroll, may be found here(link)

Bottom Line

Like any public health strategy, a vaccine’s risks must be weighed against its benefits. Gardasil can provide needed protection for women, especially for those who are at high risk of getting cervical cancer as well as individuals who cannot get routine Pap smears or HPV testing. Please consult your physician if you have any questions.

All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.

The National Center for Health Research is a nonprofit, nonpartisan research, education and advocacy organization that analyzes and explains the latest medical research and speaks out on policies and programs. We do not accept funding from pharmaceutical companies or medical device manufacturers. Find out how you can support us here.


    1. Centers for Disease Control and Prevention (CDC) (2009) Genital HPV Infection Fact Sheet. Retrieved from
    2. Stewart J. Gardasil 9 (human papillomavirus 9-valent vaccine, recombinant) FDA Approval History. Updated June 14, 2020.
    3. FDA approves expanded use of Gardasil 9 to include individuals 27 through 45 years old. U.S. Food and Drug Administration. Published October 5, 2018.
    4. Food and Drug Administration (FDA) (2008 Sept. 12). FDA Approves Expanded Uses for Gardasil to Include Preventing Certain Vulvar and Vaginal Cancers.
    5. Kjaer SK, Nygard M, Sundstrom K, et al. Final analysis of a 14-year long-term follow-up study of the effectiveness and immunogenicity of the quadrivalent human papillomavirus vaccine in women from four nordic countries. EClinicalMedicine. 2020;23:100401.
    6. Mulcahy N. GSK’s HPV Vaccine, Cervarix, No Longer Available in US. Medscape. Published October 24, 2016.
    7. Human Papillomavirus (HPV) Vaccines. National Cancer Institute. Published September 9, 2019.
    8. HPV Vaccine Safety and Effectiveness Data. Centers for Disease Control and Prevention. Published November 15, 2019.
    9. Safety Information for HPV Vaccine. Centers for Disease Control and Prevention. Updated September 9, 2020.
    10. Gee J, Sukumaran L, Weintraub E. Risk of Guillain-Barré Syndrome following quadrivalent human papillomavirus vaccine in the Vaccine Safety Datalink. Vaccine. 2017;35(43):5756-5758.
    11. Andrews N, Stowe J, Miller E. No increased risk of Guillain-Barré syndrome after human papilloma virus vaccine: A self-controlled case-series study in England. Vaccine. 2017;35(13):1729-1732.
    12. Meites E, Szilagyi PG, Chesson HW, Unger ER, Romero JR, Markowitz LE. Human Papillomavirus Vaccination for Adults: Updated Recommendations of the Advisory Committee on Immunization Practices. MMWR Morb Mortal Wkly Rep. 2019;68:698–702.
    13. Centers for Disease Control. HPV Vaccines.
    14. Garland SM, Hernandez-Avila M, Wheeler CM, et al. (2007) Quadrivalent vaccine against human papillomavirus to prevent anogenital diseases. New England Journal of Medicine, 356, 1928-43.
    15. FDA approves expanded use of Gardasil 9 to include individuals 27 through 45 years old. U.S. Food and Drug Administration. Published October 5, 2018.
    16. Meites E, Szilagyi PG, Chesson HW, et al. Human Papillomavirus Vaccination for Adults: Updated Recommendations of the Advisory Committee on Immunization Practices. MMWR Morb Mortal Wkly Rep. 2019;68:698–702.
    17. VFC. Centers for Disease Control and Prevention. Published September 1, 2020. Accessed September 23, 2020.
    18. Withers R. People Ages 27 to 45 Can Now Get the HPV Vaccine. But Will Insurance Cover It? Slate Magazine. Published October 9, 2018.
    19. Centers for Disease Control. Advisory Committee On Immunization Practices: Vaccines For Children Program – Vaccines To Prevent Human Papillomavirus. October 19, 2016.