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Human papillomavirus vaccine: Safe, effective, underused

Cleveland Clinic Journal of Medicine. 2013 January;80(1):49-60 | 10.3949/ccjm.80a.12084
January 1, 2013|Cleveland Clinic Journal of Medicine
Xian Wen Jin, MD, PhD, FACP;Laura Lipold, MD;Andrea Sikon, MD, FACP;Ellen Rome, MD, MPH
Author and Disclosure Information

Xian Wen Jin, MD, PhD, FACP
Department of Internal Medicine, Medicine Institute, Cleveland Clinic; Assistant Professor of Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH

Laura Lipold, MD
Director, Primary Care Women’s Health, Medicine Institute, Cleveland Clinic; Clinical Assistant Professor of Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH

Andrea Sikon, MD, FACP
Chair, Department of Internal Medicine, Medicine Institute; Staff, Center for Specialized Women’s Health, Obstetrics and Gynecology and Women’s Health Institute; and Women’s Professional Staff Association, Cleveland Clinic; Assistant Professor of Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH

Ellen Rome, MD, MPH
Head, Section of Adolescent Medicine, Department of General Pediatrics, Cleveland Clinic Children’s Hospital; Professor of Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH

Address: Xian Wen Jin, MD, PhD, Department of Internal Medicine, G10, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195; e-mail jinx@ccf.org

Dr. Jin has disclosed that he is one the speakers' bureau for Merck.

Dr. Rome has disclosed that she is on the speakers' bureau for Merck.

ABSTRACTVaccination against human papillomavirus (HPV) is safe and effective. It is recommended for females age 9 to 26 and for males age 11 to 26, yet vaccination rates are low. We review the host immune response, the data behind the recommendations for HPV vaccination, and the challenges of implementing the vaccination program.

KEY POINTS

  • Two HPV vaccines are available: a quadrivalent vaccine against HVP types 6, 11, 16, and 18, and a bivalent vaccine against types 16 and 18.
  • HPV causes cervical cancer, genital warts, oropharyngeal cancer, anal cancer, and recurrent respiratory papillomatosis, creating a considerable economic and health burden.
  • The host immune response to natural HPV infection is slow and weak. In contrast, HPV vaccine induces a strong and long-lasting immune response.
  • The HPV vaccines have greater than 90% efficacy in preventing cervical dysplasia and genital warts that are caused by the HPV types the vaccine contains. They are as safe as other common prophylactic vaccines.
  • HPV vaccination has been challenged by public controversy over the vaccine’s safety, teenage sexuality, mandatory legislation, and the cost of the vaccine.

HPV VACCINATION RATES ARE STILL LOW

HPV vaccine offers us the hope of eventually eradicating cervical cancer. However, the immunization program still faces many challenges, since HPV vaccination touches on issues related to adolescent sexuality, parental autonomy, and cost. As a result, HPV immunization rates remain relatively low in the United States according to several national surveys. Only 40% to 49% of girls eligible for the vaccine received even one dose, and of those who received even one dose, only 32% to 53.3% came back for all three doses.72–75 Furthermore, indigent and minority teens were less likely to finish the three-dose HPV vaccine series.

Why are the vaccination rates so low?

Parental barriers. In one survey,73 reasons that parents gave for not having their daughters vaccinated included:

  • Lack of knowledge of the vaccine (19.4%)
  • Lack of perceived need for the vaccine (18.8%)
  • Belief that their daughter was not sexually active (18.3%)
  • Clinician not recommending vaccination (13.1%).

In an effort to improve HPV vaccination rates,41 several states proposed legislation for mandatory HPV vaccination of schoolgirls shortly after licensure of the quadrivalent HPV vaccine.3 Since then, we have seen a wave of public opposition rooted in concerns and misinformation about safety, teenage sexuality, governmental coercion, and cost. Widespread media coverage has also highlighted unsubstantiated claims about side effects attributable to the vaccine that can raise parents’ mistrust of vaccines.76 Concerns have also been raised about a threat to parental autonomy in how and when to educate their children about sex.77

Moreover, the vaccine has raised ethical concerns in some parents and politicians that mandatory vaccination could undermine abstinence messages in sexual education and may alter sexual activity by condoning risky behavior.78 However, a recent study indicated that there is no significant change in sexual behavior related to HPV vaccination in young girls.79

In 2012, Mullins et al80 also found that an urban population of adolescent girls (76.4% black, 57.5% sexually experienced) did not feel they could forgo safer sexual practices after first HPV vaccination, although the girls did perceive less risk from HPV than from other sexually transmitted infections after HPV vaccination (P < .001).80 Inadequate knowledge about HPV-related disease and HPV vaccine correlated with less perceived risk from HPV after vaccination among the girls, and a lack of knowledge about HPV and less communication with their daughters about HPV correlated with less perceived risk from HPV in the mothers of the study population.81

Health-care-provider barriers. Physician endorsement of vaccines represents a key predictor of vaccine acceptance by patients, families, and other clinicians.82–84 In 2008, a cross-sectional, Internet-based survey of 1,122 Texas pediatricians, family practice physicians, obstetricians, gynecologists, and internal medicine physicians providing direct patient care found that only 48.5% always recommended HPV vaccination to girls.74 Of all respondents, 68.4% were likely to recommend the vaccine to boys, and 41.7% agreed with mandated vaccination. Thus, more than half of the physicians were not following the current recommendations for universal HPV vaccination for 11- to -12-year-olds.

In a survey of 1,013 physicians during the spring and summer of 2009, only 34.6% said they always recommend HPV vaccination to early adolescents, 52.7% to middle adolescents, and 50.2% to late adolescents and young adults.85 Pediatricians were more likely than family physicians and obstetrician-gynecologists to always recommend HPV vaccine across all age groups (P < .001). Educational interventions targeting various specialties may help overcome physician-related barriers to immunization.85

Financial barriers. HPV vaccine, which must be given in three doses, is more expensive than other vaccines, and this expense is yet another barrier, especially for the uninsured.86 Australia launched a government-funded program of HPV vaccination (with the quadrivalent vaccine) in schools in 2007, and it has been very successful. Garland et al87 reported that new cases of genital warts have decreased by 73% since the program began, and the rate of high-grade abnormalities on Papanicolaou testing has declined by a small but significant amount.

For HPV vaccination to have an impact on public health, vaccination rates in the general population need to be high. In order to achieve these rates, we need to educate our patients on vaccine safety and efficacy and counsel vaccine recipients about the prevention of sexually transmitted infections and the importance of regular cervical cancer screening after age 21. Clinicians can actively “myth-bust” with patients, who may not realize that the vaccine should be given despite a history of HPV infection or abnormal Pap smear.

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