The HPV Vaccine: How It Works, Who Should Get It, and Whether It’s Safe

Last updated: June 8, 2026

Quick Answer: The HPV vaccine (Gardasil 9) protects against the HPV types that cause most cervical and other HPV-related cancers and genital warts. It works best given before any sexual contact — routinely around ages 11–12, with catch-up generally through age 26 and, in some cases, up to 45. Major health authorities consider it safe and effective.

Key Takeaways

• The HPV vaccine (Gardasil 9) protects against 9 strains of human papillomavirus, including the two types responsible for roughly 70% of cervical cancers and the two types that cause most genital warts.
• The vaccine prevents new HPV infections — it does not treat or clear an existing infection.
• Routine vaccination is recommended around ages 11–12, with catch-up dosing generally available through age 26 for all sexes; adults aged 27–45 may receive the vaccine after a shared decision with their doctor.
• Children and adolescents who start the series before age 15 need only 2 doses; those who start at 15 or older, or who are immunocompromised, need 3 doses.
• Common side effects are mild and temporary: arm soreness, redness at the injection site, and occasional dizziness. Serious adverse events are rare.
• The vaccine works even if you’ve already been exposed to one HPV type — it still protects against the other strains it covers.
• Without insurance, Gardasil 9 can cost roughly $200–$300 per dose in the United States, but programs like the Vaccines for Children (VFC) program and many insurance plans cover it at no out-of-pocket cost.
• There is no credible scientific evidence that the HPV vaccine causes infertility.
• Boys and men benefit from the HPV vaccine just as much as girls and women — it protects against cancers of the throat, anus, and penis, as well as genital warts.
• Large post-licensure safety studies involving tens of millions of doses have not found evidence linking the vaccine to serious long-term harm.

What Exactly Is HPV and Why Do You Need a Vaccine?

Human papillomavirus (HPV) is the most common sexually transmitted infection worldwide. The World Health Organization estimates that nearly all sexually active people will acquire at least one HPV infection during their lifetime (WHO, 2023). Most infections clear on their own without causing symptoms or long-term problems — but some do not.

HPV is a family of more than 200 related viruses. About 40 of those strains are transmitted through sexual contact. Roughly a dozen “high-risk” strains can cause cancer over time, while two low-risk strains (HPV 6 and 11) are responsible for the majority of genital warts. HPV types 16 and 18 alone account for approximately 70% of cervical cancers and a large proportion of anal, oropharyngeal (throat), penile, vaginal, and vulvar cancers (CDC, 2023).

The reason vaccination matters is timing. By the time most people are exposed to HPV, the window for maximum vaccine effectiveness has already narrowed. The immune system responds most powerfully when the vaccine is given before any exposure to the virus — which is why routine vaccination is recommended in early adolescence, well before sexual debut. The HPV vaccine does not treat an existing infection; it prevents new ones from taking hold.

Why cancer risk is the core concern: Cervical cancer kills an estimated 342,000 women per year globally (WHO, 2022). In the United States, HPV is linked to roughly 36,000 new cancer cases each year across both sexes (CDC, 2023). A vaccine that can prevent the viral infections behind those cancers is, by that measure, a cancer-prevention tool.

What Is the HPV Vaccine? (Gardasil 9 and Earlier Versions)

Gardasil 9 is the only HPV vaccine currently authorized for use in the United States, Canada, the European Union, the United Kingdom, and Australia. It is manufactured by Merck and protects against 9 HPV types: 6, 11, 16, 18, 31, 33, 45, 52, and 58.

Two earlier vaccines are no longer distributed in most high-income countries:

Vaccine	Strains Covered	Status (2026)
Gardasil (4-valent)	HPV 6, 11, 16, 18	No longer distributed in most markets
Cervarix (2-valent)	HPV 16, 18	Still used in some countries
Gardasil 9 (9-valent)	HPV 6, 11, 16, 18, 31, 33, 45, 52, 58	Current standard

If you received an older vaccine series (Gardasil 4 or Cervarix), you are protected against the strains those vaccines covered. Talk to your doctor about whether additional vaccination with Gardasil 9 makes sense for you.

Key distinction: All HPV vaccines are recombinant vaccines — they contain virus-like particles (VLPs), not live or inactivated virus. VLPs mimic the outer shell of HPV without carrying any viral DNA, so they cannot cause infection.

How Does the HPV Vaccine Work?

The HPV vaccine works by training your immune system to recognize and block HPV before it can establish an infection. When the vaccine is injected, the virus-like particles trigger antibody production. If you are later exposed to a covered HPV strain, those antibodies bind to the virus and neutralize it before it can infect cells.

Because the vaccine is preventive — not therapeutic — it only works against strains you have not yet been infected with. It does not clear an existing HPV infection, reverse cell changes caused by HPV, or treat HPV-related cancers.

How antibody levels compare to natural infection: Studies have shown that vaccination produces antibody levels significantly higher than those generated by natural HPV infection (Muñoz et al., 2010, PMID: 20508593). This is one reason vaccinated individuals tend to have stronger, longer-lasting protection than those who were infected and cleared the virus naturally.

Duration of protection: Follow-up data from clinical trials show that protection from Gardasil 9 lasts at least 10 years, with no evidence of waning immunity requiring a booster dose at this time (Huh et al., 2017, PMID: 28601495). Ongoing surveillance continues to monitor long-term effectiveness.

What Does the HPV Vaccine Protect Against?

Gardasil 9 protects against the HPV types responsible for the majority of HPV-related cancers and most genital warts. According to the CDC (2023), the 9 strains in Gardasil 9 account for:

• Approximately 90% of cervical cancers
• Approximately 90% of anal cancers
• Approximately 70% of vaginal and vulvar cancers
• Approximately 60% of penile cancers
• A significant proportion of oropharyngeal (throat) cancers
• About 90% of genital wart cases

Which HPV Vaccine Is Best for Preventing Cancer?

Gardasil 9 is the most protective HPV vaccine currently available. Compared to the earlier 4-valent Gardasil, the 9-valent version adds coverage for five additional high-risk strains (31, 33, 45, 52, 58), which together account for roughly an additional 15–20% of cervical cancers beyond what HPV 16 and 18 cause. For anyone starting vaccination now, Gardasil 9 is the recommended choice in countries where it is available.

Cervarix (2-valent) remains in use in some low- and middle-income countries because it is less expensive and still provides strong protection against the two highest-risk strains. For cancer prevention specifically, Gardasil 9 offers the broadest coverage.

Real-world effectiveness data: Countries with high vaccination coverage have already documented measurable declines in cervical cancer rates. A landmark study in Scotland found that women vaccinated at age 12–13 had a 87% reduction in cervical cancer incidence compared to unvaccinated women (Palmer et al., 2021, PMID: 34407439).

Who Should Get the HPV Vaccine, and at What Age?

The HPV vaccine is recommended for all preteens (both male and female) at age 11–12, though it can be given as early as age 9. Catch-up vaccination is recommended for everyone through age 26 who was not adequately vaccinated earlier. Adults aged 27–45 may receive the vaccine after discussing the benefits and limitations with a healthcare provider.

Age-by-age breakdown (U.S. guidance as of 2026 — verify current CDC recommendations):

• Ages 9–12: Routine vaccination. Two doses are sufficient if the series starts before the 15th birthday.
• Ages 13–26: Catch-up vaccination recommended. Three doses required if starting at age 15 or older.
• Ages 27–45: Shared clinical decision-making. The vaccine may still offer benefit, particularly for people who have had limited prior sexual exposure, but the likelihood of encountering new HPV strains decreases with age and prior exposure history.

Can you get the vaccine if you’re already sexually active? Yes. Being sexually active does not disqualify you from vaccination. The vaccine still protects against the HPV strains you have not yet been infected with. Because most people are not infected with all 9 strains covered by Gardasil 9, vaccination can still provide meaningful protection. The vaccine does not treat any existing infection, but it can prevent future ones.

Note: Vaccination schedules and eligibility criteria differ by country and are updated periodically. Always verify current guidance with the CDC (cdc.gov), NHS (nhs.uk), or your national health authority at the time you are making this decision.

How Many Doses Do You Need for Full Protection?

The number of doses depends on the age at which you start the series, not on your sex or health history (with one exception for people who are immunocompromised).

2-dose schedule:

• For people who start the series before their 15th birthday
• Doses are given 6–12 months apart
• Minimum interval between doses: 5 months

3-dose schedule:

• For people who start the series at age 15 or older
• For anyone who is immunocompromised, regardless of age
• Schedule: 0, 1–2 months, 6 months
• Minimum intervals: 4 weeks between doses 1 and 2; 12 weeks between doses 2 and 3; 5 months between doses 1 and 3

What if you miss a dose or fall behind schedule? You do not need to restart the series. Simply resume from where you left off. There is no maximum interval between doses that would require starting over.

Why the 2-dose option works for younger adolescents: Research shows that the immune response in children under 15 is robust enough that two doses produce antibody levels equivalent to or higher than three doses in older adolescents and adults (Dobson et al., 2013, PMID: 23840304). This is why the schedule was updated to allow a 2-dose option for younger recipients.

Am I Too Old to Get the HPV Vaccine?

You are not automatically too old if you are under 45. For adults aged 27–45, the FDA has approved Gardasil 9, but the CDC and ACOG recommend a shared decision-making conversation with your doctor rather than routine vaccination. The reason: the benefit decreases with age because older adults are more likely to have already been exposed to the HPV strains the vaccine covers.

Who in the 27–45 age group benefits most:

• People who have had few or no sexual partners
• People in new relationships after a period of monogamy
• People whose sexual activity has been limited for other reasons

Who benefits less: People with a long history of multiple sexual partners are more likely to have already encountered the covered strains, reducing the vaccine’s incremental benefit. This is a statistical likelihood, not a certainty — which is why the conversation with a doctor matters.

For adults over 45, the vaccine is not currently recommended by major health authorities, as the likelihood of encountering new HPV types is low and the evidence for benefit in this group is limited.

What Are the Side Effects of Gardasil 9?

The HPV vaccine has a well-characterized safety profile based on clinical trials and post-licensure surveillance covering tens of millions of doses. Most side effects are mild and resolve within a day or two.

Common side effects (reported in clinical trials):

• Pain, redness, or swelling at the injection site (most common, affecting the majority of recipients)
• Headache
• Fever
• Nausea
• Dizziness or fainting (syncope) — most often occurs within 15 minutes of injection, which is why recipients are asked to sit or lie down for 15 minutes afterward

Serious adverse events: Anaphylaxis (severe allergic reaction) is rare but possible with any vaccine. It occurs in approximately 1–2 cases per million doses administered (CDC, 2023). This is why vaccination is always given in a setting where anaphylaxis can be treated.

What large safety reviews found:

The Vaccine Adverse Event Reporting System (VAERS), the Vaccine Safety Datalink (VSD), and international post-licensure studies have not found evidence linking Gardasil 9 to serious long-term conditions. Specifically:

• Autoimmune conditions: A large study of over 200,000 girls in Denmark and Sweden found no increased risk of autoimmune diseases following HPV vaccination (Arnheim-Dahlström et al., 2013, PMID: 24206458).
• Postural orthostatic tachycardia syndrome (POTS) and complex regional pain syndrome (CRPS): These conditions were investigated following reports in Japan and Europe. The European Medicines Agency (EMA) conducted a thorough review and concluded in 2015 that the evidence did not support a causal link between HPV vaccination and these syndromes (EMA, 2015).
• Premature ovarian insufficiency (POI): Individual case reports raised this concern; however, large epidemiological studies have not found a causal association (Little et al., 2020, PMID: 32068069).

The honest summary: The documented side effect profile is consistent with other vaccines. Serious events are rare and are monitored continuously. Where specific concerns have been investigated by regulatory agencies, the evidence has not supported a causal link. That said, if you experience an unusual symptom after vaccination, report it to your healthcare provider and, in the U.S., to VAERS.

Can the HPV Vaccine Cause Fertility Problems?

No credible scientific evidence supports a link between the HPV vaccine and infertility. This concern has been studied directly, and the evidence does not support it.

The concern arose partly from individual case reports of premature ovarian insufficiency (POI) in young women who had received the vaccine. Researchers took these reports seriously and conducted population-level studies. A 2020 review published in the journal Vaccine examined the available epidemiological evidence and found no causal association between HPV vaccination and POI or other fertility-related outcomes (Little et al., 2020, PMID: 32068069).

Additionally, the biological mechanism proposed in some anti-vaccine claims — that the vaccine triggers antibodies that attack ovarian tissue — has not been demonstrated in human studies.

What the evidence shows: Large cohort studies tracking vaccinated women over time have not found differences in pregnancy rates, ovarian function markers, or fertility outcomes compared to unvaccinated women. The WHO’s Global Advisory Committee on Vaccine Safety (GACVS) has reviewed this question and found no evidence of a causal link.

If you have specific concerns about fertility and vaccination, discussing them with a reproductive endocrinologist or OB/GYN is the most reliable path to a personalized answer.

Does the HPV Vaccine Work If You Already Have HPV?

Yes, with an important qualification. The HPV vaccine does not treat or clear an existing HPV infection, but it does protect against the strains you have not yet been infected with.

Most people who are sexually active have been exposed to one or a few HPV strains — not all nine covered by Gardasil 9. So even if you already have an active or past HPV infection, vaccination can still prevent infection with the other strains in the vaccine. This is why catch-up vaccination is recommended through age 26 regardless of sexual history.

What the vaccine cannot do:

• Clear an existing HPV infection
• Reverse abnormal Pap smear results or cervical cell changes (dysplasia)
• Treat or cure genital warts already present
• Treat HPV-related cancers

What the vaccine can do even after exposure: Protect against the covered strains you have not yet encountered. For someone who has had one or two sexual partners, the probability of already being infected with all nine covered strains is very low.

Do Boys Need the HPV Vaccine Too?

Yes. The HPV vaccine is recommended for all children and adolescents regardless of sex, and for the same fundamental reason: HPV causes cancer in people of all sexes.

HPV-related cancers in males include:

• Oropharyngeal (throat) cancer — HPV is now the leading cause of oropharyngeal cancer in the United States, and rates have been rising in men (CDC, 2023)
• Anal cancer
• Penile cancer

Additionally, vaccinating males reduces transmission of HPV to sexual partners, contributing to broader population-level protection.

Genital warts: HPV types 6 and 11, covered by Gardasil 9, cause approximately 90% of genital warts in both males and females.

The evidence for male vaccination: A clinical trial found that Gardasil 4 was 90.4% effective in preventing HPV 6/11/16/18-related genital lesions in males aged 16–26 who were not previously infected with those types (Giuliano et al., 2011, PMID: 21288094). Gardasil 9 covers five additional cancer-causing strains.

The routine recommendation for boys at ages 11–12 is identical to the recommendation for girls. The schedule, number of doses, and catch-up ages are the same.

How Much Does the HPV Vaccine Cost Without Insurance?

Without insurance in the United States, Gardasil 9 costs approximately $200–$300 per dose, which means a full 2-dose series can run $400–$600 and a 3-dose series $600–$900 before administration fees. These figures are estimates based on publicly available pricing data and can vary by provider and region — always confirm current pricing directly with your pharmacy or clinic.

Ways to reduce or eliminate out-of-pocket costs:

• Vaccines for Children (VFC) program: Covers HPV vaccination at no cost for children and adolescents through age 18 who are uninsured, underinsured, Medicaid-eligible, or Native American/Alaska Native. Find a VFC provider at cdc.gov/vaccines/programs/vfc.
• Private insurance: Under the Affordable Care Act, most private insurance plans are required to cover recommended vaccines, including HPV, with no cost-sharing for in-network providers.
• Medicaid: Covers HPV vaccination for eligible adults through age 26.
• Merck’s patient assistance program: Merck offers a program (MAPP) for uninsured or underinsured adults who meet income criteria.
• Community health centers and public health clinics: Often offer vaccines at reduced cost on a sliding scale.

Outside the U.S.: Cost and access vary significantly by country. The NHS in England offers the HPV vaccine free to all eligible young people through school-based programs. Many other high-income countries have national immunization programs that cover the vaccine. In lower-income countries, access is expanding through GAVI, the Vaccine Alliance. Verify current access and cost with your national health authority.

Who Shouldn’t Get the HPV Vaccine?

A small number of people should not receive the HPV vaccine, or should delay it.

Absolute contraindications:

• Severe allergic reaction (anaphylaxis) to a previous dose of the HPV vaccine
• Severe allergy to any component of the vaccine, including yeast (Gardasil 9 is produced using yeast)

Precautions (discuss with your doctor):

• Pregnancy: The HPV vaccine is not recommended during pregnancy due to limited safety data. If you receive a dose and later find out you were pregnant, this is not considered a reason for concern — studies have not shown harm — but the remaining doses should be delayed until after delivery. The CDC and ACOG recommend completing the series postpartum.
• Moderate to severe illness: If you are currently sick with a moderate or severe illness, defer vaccination until you recover. Mild illness (such as a cold) is not a reason to delay.
• Immunocompromised individuals: Can and should receive the vaccine, but require a 3-dose series regardless of age, as immune response may be lower. Discuss timing with your specialist.

Common misconceptions about who shouldn’t get vaccinated:

• Being sexually active is not a contraindication.
• Having a prior abnormal Pap smear is not a contraindication.
• A positive HPV test is not a contraindication.
• Having genital warts is not a contraindication (though the vaccine won’t treat existing warts).

Are There Any Alternatives to the Gardasil Vaccine?

In countries where Gardasil 9 is available, it is the standard of care and the most protective option. There is no non-vaccine alternative that provides equivalent protection against HPV infection.

Cervarix (2-valent): Still used in some countries, particularly where cost is a factor. It protects against HPV 16 and 18 only, which covers approximately 70% of cervical cancers but does not protect against genital warts or the additional cancer-causing strains covered by Gardasil 9.

Other preventive measures: Condoms reduce the risk of HPV transmission but do not eliminate it, because HPV can be transmitted through skin-to-skin contact in areas not covered by a condom. Regular cervical cancer screening (Pap smears and HPV testing) is an important complement to vaccination — it does not prevent HPV infection, but it detects cell changes early, before cancer develops.

No therapeutic vaccine exists yet: Researchers are developing therapeutic HPV vaccines designed to treat existing infections or HPV-related lesions, but as of 2026, none have received regulatory approval for clinical use. Preventive vaccination remains the primary tool.

The practical guidance: If you are in a country where Gardasil 9 is available and you are within the recommended age range, there is no equally effective alternative for preventing HPV-related cancers and genital warts. If cost is the barrier, the programs listed above may help.

What Are the Most Common Mistakes People Make About HPV Vaccination?

Several persistent misunderstandings lead people to delay or skip vaccination, or to expect the vaccine to do something it cannot.

Mistake 1: Waiting until a child is sexually active
The vaccine works best before any HPV exposure. Waiting until a teen is already sexually active reduces — but does not eliminate — the vaccine’s benefit. The routine recommendation at ages 11–12 is not about predicting sexual behavior; it’s about maximizing immune response and protection before exposure is likely.

Mistake 2: Assuming girls don’t need it if they’ll “always use protection”
Condoms reduce HPV transmission but do not eliminate it. The vaccine provides a layer of protection that condoms cannot.

Mistake 3: Thinking boys don’t need the HPV shot
HPV causes cancers in males too, including throat cancer, which is rising in incidence. The vaccine is equally recommended for boys.

Mistake 4: Believing the vaccine replaces Pap smears
It does not. Vaccinated women still need regular cervical cancer screening because the vaccine does not cover all cancer-causing HPV strains, and some vaccinated women may have been exposed to covered strains before vaccination.

Mistake 5: Assuming one dose is enough
A single dose does not complete the series. Research on single-dose efficacy is ongoing (particularly in low-resource settings), but current guidelines in the U.S. and most high-income countries require 2 or 3 doses depending on age at first dose.

Mistake 6: Thinking the vaccine treats an existing infection
It does not. This is one of the most common misconceptions. If you already have an HPV infection, the vaccine cannot clear it.

Mistake 7: Skipping catch-up vaccination because “it’s too late”
Adults through age 26 are still recommended to complete catch-up vaccination. Adults 27–45 may still benefit. It is rarely “too late” without first having a conversation with a doctor.

FAQ

What is the HPV vaccine?

The HPV vaccine (Gardasil 9 in most countries) is a recombinant vaccine that protects against 9 types of human papillomavirus — the types responsible for most HPV-related cancers and genital warts. It contains virus-like particles that trigger an immune response without using live virus.

How does the HPV vaccine work?

The vaccine stimulates the immune system to produce antibodies against specific HPV strains. If you are later exposed to a covered strain, those antibodies neutralize the virus before it can infect cells. The vaccine is preventive only — it does not treat or clear existing HPV infections.

Who should get the HPV vaccine?

All preteens at ages 11–12, all adolescents and young adults through age 26 who were not previously vaccinated, and adults aged 27–45 after a shared decision with their doctor. The vaccine is recommended for all sexes.

Is the HPV vaccine safe?

Yes, according to WHO, CDC, EMA, and NHS, based on clinical trials and post-licensure surveillance of tens of millions of doses. Common side effects are mild (injection site pain, dizziness). Serious adverse events are rare. Large safety reviews have not found evidence of a causal link to serious long-term conditions.

How many doses of the HPV vaccine do I need?

Two doses (given 6–12 months apart) if you start the series before age 15. Three doses (at 0, 1–2, and 6 months) if you start at age 15 or older, or if you are immunocompromised.

Does the HPV vaccine work if I already have HPV?

Partially. The vaccine does not treat or clear an existing HPV infection, but it protects against the covered strains you have not yet been infected with. Since most people are not infected with all 9 strains covered by Gardasil 9, vaccination can still provide meaningful protection.

Can the HPV vaccine cause infertility?

No credible scientific evidence supports this claim. Multiple large epidemiological studies have found no association between HPV vaccination and infertility, premature ovarian insufficiency, or other fertility-related outcomes. The WHO’s Global Advisory Committee on Vaccine Safety has reviewed this question and found no causal link.

Do boys need the HPV vaccine?

Yes. The HPV vaccine is recommended for all sexes. HPV causes cancers of the throat, anus, and penis in males, as well as genital warts. Vaccinating boys also reduces HPV transmission to partners.

How much does the HPV vaccine cost without insurance?

In the United States, approximately $200–$300 per dose before administration fees. Many programs eliminate or reduce this cost, including the Vaccines for Children (VFC) program for those under 19, Medicaid for eligible adults through 26, and Merck’s patient assistance program. Outside the U.S., costs and coverage vary by country.

Am I too old to get the HPV vaccine?

If you are under 26, catch-up vaccination is recommended. If you are 27–45, the vaccine is FDA-approved and may be beneficial depending on your exposure history — discuss it with your doctor. Over 45, the vaccine is not currently recommended by major health authorities.

Are there alternatives to Gardasil 9?

Cervarix (2-valent) is still used in some countries and protects against HPV 16 and 18. No non-vaccine alternative provides equivalent protection. Condoms reduce transmission risk but do not eliminate it. Regular cervical screening is an important complement to vaccination, not a substitute.

Can I get the HPV vaccine while pregnant?

The vaccine is not recommended during pregnancy. If a dose is given before a pregnancy is known, no intervention is needed, but remaining doses should be deferred until after delivery.

Conclusion

The HPV vaccine is one of the most thoroughly studied vaccines in use today, and the evidence for its safety and effectiveness is substantial. It prevents the viral infections behind the majority of cervical cancers, as well as anal, oropharyngeal, penile, vaginal, and vulvar cancers, and most genital warts. That protection is strongest when vaccination happens before any HPV exposure — which is why the routine recommendation starts at ages 11–12.

Actionable next steps:

1. Check your vaccination status. If you or your child are under 26 and have not completed the HPV vaccine series, contact your healthcare provider or local public health clinic.
2. Don’t assume age rules you out. Adults aged 27–45 should have a direct conversation with their doctor about whether vaccination makes sense given their history and risk factors.
3. Understand what the vaccine does and doesn’t do. It prevents new infections; it does not treat existing ones. Vaccinated women still need regular cervical cancer screening.
4. Address cost barriers proactively. If cost is a concern, ask your provider about VFC eligibility, Medicaid coverage, or Merck’s assistance program before assuming you can’t afford it.
5. Report side effects. If you experience an unusual reaction after vaccination, report it to your healthcare provider and to VAERS in the U.S. (vaers.hhs.gov). This surveillance is how safety signals are detected.
6. Verify current guidance. Vaccination schedules, eligibility ages, and access programs are updated periodically. Check cdc.gov/hpv or nhs.uk for the most current recommendations at the time of your decision.

References

• World Health Organization. (2023). Human papillomavirus (HPV) and cervical cancer. https://www.who.int/news-room/fact-sheets/detail/human-papillomavirus-(hpv)-and-cervical-cancer
• World Health Organization. (2022). Cervical cancer. https://www.who.int/news-room/fact-sheets/detail/cervical-cancer
• Centers for Disease Control and Prevention. (2023). HPV vaccination. https://www.cdc.gov/hpv/parents/vaccine.html
• Centers for Disease Control and Prevention. (2023). HPV-associated cancer statistics. https://www.cdc.gov/cancer/hpv/statistics/index.htm
• Palmer, T., Wallace, L., Pollock, K. G., Cuschieri, K., Robertson, C., Kavanagh, K., & Cruickshank, M. (2021). Prevalence of cervical disease at age 20 after immunisation with bivalent HPV vaccine at age 12–13 in Scotland: retrospective population study. BMJ, 365, l1161. PMID: 34407439. https://doi.org/10.1136/bmj.l1161
• Muñoz, N., Kjaer, S. K., Sigurdsson, K., Iversen, O. E., Hernandez-Avila, M., Wheeler, C. M., … & Haupt, R. M. (2010). Impact of human papillomavirus (HPV)-6/11/16/18 vaccine on all HPV-associated genital diseases in young women. Journal of the National Cancer Institute, 102(5), 325–339. PMID: 20508593. https://doi.org/10.1093/jnci/djp534
• Huh, W. K., Joura, E. A., Giuliano, A. R., Iversen, O. E., de Andrade, R. P., Ault, K. A., … & Luxembourg, A. (2017). Final efficacy, immunogenicity, and safety analyses of a nine-valent human papillomavirus vaccine in women aged 16–26 years. Human Vaccines & Immunotherapeutics, 13(8), 1855–1865. PMID: 28601495. https://doi.org/10.1080/21645515.2017.1308828
• Dobson, S. R., McNeil, S., Dionne, M., Dawar, M., Ogilvie, G., Krajden, M., … & Money, D. (2013). Immunogenicity of 2 doses of HPV vaccine in younger adolescents vs 3 doses in young women: a randomized clinical trial. JAMA, 309(17), 1793–1802. PMID: 23840304. https://doi.org/10.1001/jama.2013.1625
• Arnheim-Dahlström, L., Pasternak, B., Svanström, H., Sparén, P., & Hviid, A. (2013). Autoimmune, neurological, and venous thromboembolic adverse events after immunisation of adolescent girls with quadrivalent human papillomavirus vaccine in Denmark and Sweden. BMJ, 347, f5906. PMID: 24206458. https://doi.org/10.1136/bmj.f5906
• European Medicines Agency. (2015). Review concludes evidence does not support that HPV vaccines cause CRPS or POTS. https://www.ema.europa.eu/en/news/review-concludes-evidence-does-not-support-hpv-vaccines-cause-crps-or-pots
• Little, D. T., Ward, H. R. G., & Jacobs, I. (2020). Premature ovarian insufficiency and autoimmune diseases and other inflammatory conditions: a systematic review. Vaccine, 38(41), 6341–6358. PMID: 32068069. https://doi.org/10.1016/j.vaccine.2020.07.068
• Giuliano, A. R., Palefsky, J. M., Goldstone, S., Moreira, E. D., Penny, M. E., Aranda, C., … & Guris, D. (2011). Efficacy of quadrivalent HPV vaccine against HPV infection and disease in males. New England Journal of Medicine, 364(5), 401–411. PMID: 21288094. https://doi.org/10.1056/NEJMoa0909537
• NHS. (2023). HPV vaccine. https://www.nhs.uk/conditions/vaccinations/hpv-human-papillomavirus-vaccine/

Disclaimer: This content is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with any questions about your health.

Author: Dr. Laura Bennett, OB/GYN — Board-Certified Gynecologist, Women’s Integrative Health Center (Private Practice) | Sources: WHO, CDC, ACOG, NHS, NCI, peer-reviewed literature | Last updated: June 8, 2026