November 14, 2022
By Diana Kinney

Human papillomavirus (HPV) is the most prevalent sexually transmitted infection (STI) in the United States; approximately 14 million Americans become infected each year.¹ Although HPV most often presents asymptomatically and clears without major clinical consequence, it can persist and progress to anogenital warts, precancers or even cancers of the cervix, other anogenital tract and oropharynx. In the United States, over 40,000 cancers are diagnosed each year in both men and women that are attributed to HPV infection.² In women, HPV is thought to be linked to greater than 90% of cervical cancer cases and approximately 70% of vaginal and vulvar cancers.

More than 200 kinds of HPV have been identified and they are categorized based on their epidemiologic association with cervical cancer. Most types of HPV are low risk, as they do not cause any symptoms, lesions or warts. However, certain strains of HPV, such as types 16 and 18, are considered higher risk for causing precancers and cancer. There is no cure or treatment for an active infection so the importance of primary prevention through receiving the HPV vaccine cannot be overstated. HPV vaccines are approximately 97% effective at preventing infection, and the 9-valent vaccine covers almost 90% of the HPV associated with cervical cancer.³ It is crucial to note that HPV vaccination does not replace the need for regular screening (every three to five years) with Pap smears in women between the ages of 21 and 65.

As of now, there are three vaccines against HPV available and recommended by the Centers for Disease Control and Prevention (CDC) for both men and women prior to becoming sexually active. Vaccination can be initiated as early as age 9 with the highest effectiveness being shown when given between the ages of 11 and 12.⁴ The HPV vaccine consists of two or three doses depending on age and vaccine type and is recommended for all individuals through age 26, if not vaccinated already. Beyond age 26, the guidelines do not specifically recommend catch-up vaccination but suggest that clinicians and patients should make decisions about HPV vaccination on an individual basis for persons aged 27 to 45.

Prior to HPV vaccine introduction in 2006, the CDC estimated that nearly 79 million Americans were infected with HPV.⁵ Data within 10 years after vaccine introduction revealed that the prevalence of four HPV strains (types 6, 11, 16 and 18) decreased approximately 86% among females ages 14 through 19 years and 71% among females ages 20 to 24.⁶ Reductions in anogenital wart prevalence were also identified following HPV vaccine introduction in both young women and men.

Despite these decreases in prevalence, surveys have shown that there is still a lack of parental knowledge and confidence regarding the need and safety of HPV vaccination in young preteens and teens.⁷ This data point cannot be ignored, as the highest antibody titer response from HPV vaccination occurs between the ages of 11 and 12, a time when parents of young women are largely responsible for this decision. A population-based study looking at over 1.6 million girls and women from Sweden showed that there might be as high as an 88% reduction in the incidence of cervical cancer in individuals who are vaccinated for HPV before the age of 17.⁸ Thus, it is essential that health care providers from pediatricians to college student health physicians address any misinformation, hesitancy or safety concerns that both the patients and parents may have about the vaccine. This call to action becomes especially important given that the HPV vaccination-completion rates remain less than 50% in most states.⁹

Lastly, this discussion warrants the need to intensify HPV prevention and education initiatives for non-Hispanic Black children, as the rates of HPV infections are higher in Black women than those in other ethnic groups.¹⁰ Further efforts need to be implemented to provide information to families in Black, rural and underserved communities regarding HPV and pro-vaccine motivation tools.

Key Takeaways

• HPV is the most common STI in the United States
• The vast majority of HPV infections are asymptomatic and do not result in clinical disease
• HPV infections can clinically manifest as anogenital warts, cervical precancers and cancer
• Routine HPV vaccination is recommended for females and males at age 11 to 12 or prior to sexual debut
• Pap smears are recommended for cervical cancer screening in women every three years starting at age 21; interval increases to five years starting at age 30 until age 65

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Sources/Resources:

1. STD Facts - Human Papillomavirus (HPV). cdc.gov/std/hpv/stdfact-hpv.htm. Accessed 8 Sept. 2022.
2. "Cancers Associated with Human Papillomavirus, United States, 2014–2018." Centers for Disease Control and Prevention. United States Cancer Statistics Data Brief 2021;26.
3. "Addressing HPV vaccine myths: practical information for healthcare providers." Bednarczyk RA. 2019. Hum Vaccin Immunother. 15(7–8):1628–1638.
4. HPV Vaccine Schedule and Dosing | CDC. cdc.gov/hpv/hcp/schedules-recommendations.html. Accessed 8 Sept. 2022.
5. "Human Papillomavirus Vaccination for Adults: Updated Recommendations of the Advisory Committee on Immunization Practices." Meites E, Szilagyi PG, Chesson HW, Unger ER, Romero JR, Markowitz LE. MMWR Morb Mortal Wkly Rep. 2019 Aug 16;68(32):698-702. doi: 10.15585/mmwr.mm6832a3. PMID: 31415491; PMCID: PMC6818701.
6. "A 12-year follow-up on the long-term effectiveness of the quadrivalent human Papillomavirus vaccine in 4 Nordic countries." Kjaer SK, Nygård M, Dillner J, Brooke Marshall J, Radley D, Li M, Munk C, Hansen BT, Sigurdardottir LG, Hortlund M, et al. 2018. Clin Infect Dis. 66(3):339–345.
7. "Parents' Knowledge and Attitude towards HPV and HPV Vaccination in Poland." Smolarczyk K, Duszewska A, Drozd S, Majewski S. Vaccines (Basel). 2022 Feb 2;10(2):228. doi: 10.3390/vaccines10020228. PMID: 35214686; PMCID: PMC8876926.
8. "HPV vaccination and the risk of invasive cervical cancer." Lei J, Ploner A, Elfström KM, Wang J, Roth A, Fang F, et al. N. Engl. J. Med. 2020;383:1340–1348. doi: 10.1056/NEJMoa1917338.
9. "Disparities in HPV vaccination rates and HPV prevalence in the United States: a review of the literature." Hirth J. Hum Vaccin Immunother. 2019;15(1):146-155. doi: 10.1080/21645515.2018.1512453. Epub 2018 Sep 6. PMID: 30148974; PMCID: PMC6363146.
10. "Racial Disparities in HPV-related Knowledge, Attitudes, and Beliefs Among African American and White Women in the USA." Ojeaga A, Alema-Mensah E, Rivers D, Azonobi I, Rivers B. J Cancer Educ. 2019 Feb;34(1):66-72. doi: 10.1007/s13187-017-1268-6. PMID: 28808906; PMCID: PMC5812850.