STD Quarterly

More education is needed to boost HPV vaccination rates in preteen girls, CDC says

When it comes to administering the vaccine for human papillomavirus (HPV), providers are following the Centers for Disease Control and Prevention's (CDC) Advisory Committee on Immunization Practices' recommendation to target all girls ages 11-12 for routine vaccination.

But how do parents figure into the vaccination picture? Results from a new national study indicate that U.S. mothers report they are less likely to vaccinate daughters under age 13 against the disease, even though the vaccine is recommended for preteen girls.1

Parental attitudes about HPV vaccines will be key determinants of adolescent vaccination, says Jessica Kahn, MD, MPH, associate professor of pediatrics and director of research training in the Division of Adolescent Medicine at Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine. Previous studies have shown that parents generally support vaccination of their children, but some parents have specific concerns about their child receiving an STD vaccine,2,3 and some are reluctant to immunize daughters in the age range targeted for vaccination, says Kahn, lead author of the research paper.

Most published studies on parental attitudes on HPV vaccines enrolled parents from a limited geographic area and were conducted prior to vaccine licensing, says Kahn. For those reasons, co-authors of the current paper decided to conduct a national, post-licensing study involving mothers of adolescent and young adult women, she explains.

"Our aims were to characterize mothers' attitudes about HPV vaccines and intention to make sure that daughters in different age groups were vaccinated; to explore mothers' intention to be vaccinated themselves, if the vaccine were recommended for women their age; and to identify factors (demographic, attitudinal, and behavioral) linked to intention to vaccinate a daughter in different age groups," Kahn states.

Researchers surveyed 10,521 mothers of adolescents enrolled in the Growing Up Today Study, a longitudinal study of the children of mothers participating in the Nurses Health Study II between June 2006 and February 2007. In the study, while 86% of mothers registered intention to vaccinate a 16- to 18-year-old daughter, and 68% said they intended to vaccinate a 13- to 15-year-old daughter, fewer than half (48%) registered intention to vaccinate a 9- to 12-year-old daughter.1

The most powerful individual predictors that were most associated with mothers' likelihood to vaccinate their younger daughters were belief that HPV vaccination would provide protection against cervical cancer, belief that vaccinated girls would not practice riskier sex, belief that a daughter's clinician would recommend HPV vaccines for her, and belief that a daughter is at risk for HPV infection.1

Researchers from Indiana University, the University of Texas Medical Branch Galveston and Harvard University Medical School participated in the analysis, which was funded by the American Cancer Society.

What's the next step?

Since mothers' personal beliefs play such an important role in their decisions to have younger daughters immunized against HPV, the development of evidence-based messages that emphasize adolescent girls' risk for HPV infection, the effectiveness of the vaccine in preventing cervical cancer, and clinician endorsement of vaccination may increase the acceptability of the HPV vaccine among parents and help to maximize HPV vaccine uptake, says Kahn. The research team intends to study interventions to increase mothers' willingness to vaccinate their daughters.

"Identification of factors linked to intention can help us to design evidence-based interventions to improve vaccine acceptability among mothers and thus improve vaccine uptake among their daughters," says Kahn. "Our findings can help to create key messages for these interventions."

The American Cancer Society estimates that in 2008, 11,070 women will be diagnosed with cervical cancer in the United States.4 Gardasil is designed to protect against infection from four HPV types, including two types (HPV 16 and 18) that cause about 70% of cervical cancers.

"It is very important that women be vaccinated, and because this vaccine is a preventative, not a cure, it is very important the girls be vaccinated before beginning sexual relations," says Curtis Allen, a CDC spokesman. "It is also very important that parents understand the reason for the vaccine and also that they can explain the reason for the vaccine to their young daughters."

In girls and women who have not been infected with any of the four HPV types contained in the Gardasil vaccine, research indicates that the vaccine is about 100% effective in preventing precancers of the cervix, vulva, and vagina, and genital warts caused by those HPV types.5

"Education is a very important part of any vaccine program, but it is important that parents understand why the Advisory Committee on Immunization Practices made the decisions that they did and why it is important for their daughters to be vaccinated against HPV," says Allen.

The CDC has developed an informational handbook for clinicians, "Human Papillomavirus: HPV Information for Clinicians." The handbook contains a freely reproducible handout for parents, "What Parents of Preteens/Adolescents Should Know About the HPV Vaccine." The handout is available in both English and Spanish. (To download the clinician handbook, go to the web site www.cdc.gov.)

Cover important facts about HPV with those who are vaccinated (see box.), and stress these important messages with parents:

  • The vaccine is given through a series of three shots over a six-month period. Your daughter will need to come back for the second and third shots two and six months (respectively) after the first shot. It is very important that she receive all three shots, since it is not yet known how much protection she would get from receiving only one or two shots of the vaccine.
  • The vaccine causes no serious side effects. The most common side effect is soreness at the injection site.
  • The HPV vaccine costs about $120 per dose, or $360 for the series. You may be able to get it for free or at low-cost through your health insurance plan or federal or state programs.

References

  1. Kahn J, Ding L, Huang B, et al. U.S. mothers intention to vaccinate their daughters against HPV. Presented at the annual meeting of the Pediatric Academic Societies. Honolulu; May 2008.
  2. Mays RM, Sturm LA, Zimet GD. Parental perspectives on vaccinating children against sexually transmitted infections. Soc Sci Med 2004; 58:1,405-1,413.
  3. Liddon N, Pulley L, Cockerham WC, et al. Parents'/ guardians' willingness to vaccinate their children against genital herpes. J Adolesc Health 2005; 37:187-193.
  4. Centers for Disease Control and Prevention. Genital HPV Infection. Fact sheet. Accessed at www.cdc.gov.
  5. Skjeldestad FE for the Future II Steering Committee. Prophylactic quadrivalent human papillomavirus (types 6, 11, 16, 18) L1 virus-like particle vaccine (Gardasil) reduces cervical intraepithelial neoplasia 2/3 risk. Presented at the 43rd annual meeting of the Infectious Diseases Society of America. San Francisco; October 2005.