HPV vaccine uptake remains low
Why some adolescents are not receiving the vaccine, and what can be done about it
The number of individuals who are completing the human papillomavirus (HPV) vaccine series continues to be quite low, according to several recent studies, and researchers want to know why. “Most people don't realize that there is a vaccine, that it's highly effective, and that it's available,” says Abbey Berenson, MD, MMS, PhD, director of the Center for Interdisciplinary Research in Women's Health at the University of Texas Medical Branch in Galveston.
An estimated 20 million Americans aged 15 to 49 years are currently infected with HPV, and at least 50% of sexually active men and women will contract the virus at some point in their lifetime, experts say. In addition to cervical cancer, the virus associated with vulvar, vaginal, penile, anal, and oropharyngeal cancers. The HPV vaccine was first approved by the US Food and Drug Administration in 2006, and it protects against infection from 4 strains of HPV. Two of the strains, HPV- 16 and HPV-18, account for approximately 70% of cervical cancers, whereas the other 2 strains cause approximately 90% of genital warts.
The 3-series vaccine is recommended for all girls and boys at age 11 or 12 years so that they can develop immunity before they become sexually active. The Centers for Disease Control and Prevention, the American Cancer Society, the American Academy of Pediatrics, and the American Academy of Family Physicians have all endorsed the recommendations.
Despite these recommendations, recent studies have found that many adolescents are not vaccinated against the virus. The American Cancer Society's annual report on the status of cancer published earlier this year stated that 32% of girls aged 13 to 17 years had received the HPV vaccine in 2010, and the rate was significantly lower among the uninsured (14.1%). At the same time, incidence rates for 2 HPV-associated cancers (oropharyngeal and anal) are on the rise. In addition, in 3 separate studies, researchers used data from the 2010 National Health Interview Survey, an annual cross-sectional survey tracking more than 27,000 U.S. adults.[2-4] Among the findings:
- More than 75% of women aged 18 to 26 years had not received the HPV vaccine, whereas another 10% had not receive the full 3 doses. Approximately two-thirds of women said they did not want the vaccine.
- In 2010, the first full year when the vaccine was recommended for boys, only 2% of males aged 9 to 17 years initiated the vaccine, and fewer than one-half of them (0.5%) completed the 3-dose series.
Barriers to Vaccination
Dr. Berenson, lead author of the studies, notes that although vaccine rates were particularly low among low-income and uninsured families and minority women, cost did not seem to be the major barrier, because rates also were not high among the insured. “We now have a vaccine to prevent cancer that has not been embraced by the public, and we won't see a significant decrease in abnormal Pap [Papanicolaou] smears and overall cancer rates until more people are vaccinated,” she says.
Negative publicity about the vaccine's safety, a lack of education about the vaccine, and a strong public reluctance to acknowledge the reality of teen sexual activity are all seen as barriers to HPV vaccine uptake, says Dr. Berenson. “We think that further education is needed, especially among populations that are not aware of the vaccine, such as many low-income girls and women,” she says, adding that the HPV vaccine is covered by the federal government's Vaccines for Children Program and by private insurance and Medicaid.
She and her colleagues are further exploring barriers to education, and possible solutions. They are surveying approximately 1000 mothers with children between the ages of 9 and 17 years in the University of Texas Medical Branch prenatal and well-child clinic to determine why they did or did not elect to have their children receive the HPV vaccine. After completing the survey, researchers plan to develop an intervention. Additional studies are examining how best to remind patients to complete their vaccines.
Another recent study found that a growing percentage of parents say they will not have their teen daughters vaccinated against HPV despite the fact that physicians are increasingly recommending the vaccine. The study examined 3 vaccinations routinely recommended for teenagers in the United States: the HPV vaccine, the DTaP vaccine (diphtheria, tetanus, and pertussis), and the meningococcal conjugate vaccine. The percentage of those fully immunized against HPV was substantially lower than for the other 2 vaccines. Furthermore, 40% of parents surveyed 5 years ago stated they would not have their children vaccinated against HPV, and that rate increased to 44% in 2010. Meanwhile, safety concerns regarding the vaccine quadrupled from 4.5% in 2008 to 16.4% in 2010, says the study's senior researcher, Robert Jacobson, MD, a pediatrician with the Mayo Clinic Children's Center in Rochester, Minnesota.
Large-scale studies have refuted some of the original safety concerns of the HPV vaccine, including claims that it was associated with Guillain-Barré syndrome, a clotting disorder, and some autoimmune diseases. Nevertheless, say Dr. Jacobson, “What makes the news is the initial concern. Once the study is released that shows no association, that doesn't make the headlines.”
During the same time period, an antivaccine movement gained momentum. During the 2012 presidential campaign, for example, Governor Rick Perry of Texas was criticized for trying to mandate the HPV vaccine for girls, which the state legislature later opposed. In addition, US Representative Michele Bachmann (R-Minn.) alleged that the vaccine was associated with mental retardation, although she eventually retracted the statement, Dr. Jacobson says. “This is a vaccine against cancer, but it is also a vaccine against a sexually transmitted disease, and a lot of parents would like to think their child is not ready to be exposed to that risk,” he adds. “They may use the safety explanation rather than getting into an argument with a nurse or physician about their other reasons for resistance.”
Kevin Ault, MD, professor of gynecology and obstetrics at Emory University in Atlanta, Georgia, says some parents have been concerned that vaccinating their children against HPV could lead to premature sexual activity, even though studies have not supported that claim.
Dr. Jacobson believes that physicians need to do a better job of communicating with patients about the importance of the vaccine. He has developed and is teaching a method for physicians to improve those efforts, abbreviated as “CASE.” It involves: “Corroborating” parents' concerns; making the advice “About me” (explaining that the clinician also has the same concerns, has investigated them, and has found evidence that the vaccine is very important); “Summarizing” the science very quickly; and “Explaining” the clinician's advice.
“I've talked to clinicians in a variety of settings, and I've found there is a real hunger for that sort of teaching,” he says. “The age-old approach of brochures and Web site links won't work well because parents don't have the time. You're almost hoping someone else will do the convincing.”
Parents need to understand that the vaccine generates a better immune response at the age of 11 or 12 years versus at 15 or 16 years because the body's immune system is at its peak at the earlier age, Dr. Jacobson says. He and his colleagues are attempting to determine through focus groups how to best talk to both parents and teenagers to get them engaged in making the decision to vaccinate. “I think the vaccine should be universally adopted, but I don't want it required or mandated,” he says. “I want to have conversations that will help people feel good about the decision.”
We now have a vaccine to prevent cancer that has not been embraced by the public, and we won't see a significant decrease in abnormal Pap smears and overall cancer rates until more people are vaccinated.
Dr. Ault notes that in Australia, which was one of the first countries to introduce a nationally financed HPV vaccination program for young girls and women in 2007, researchers have reported a significant decrease in the incidence of genital warts and cervical abnormalities. It is too soon to conclude whether the program will reduce cancer incidence. Australia also did not experience the vaccine opposition that occurred in the United States.
Dr. Ault and his colleagues are conducting research on how long an individual's immune system can fight the HPV virus after they have been vaccinated. They also are attempting to determine how effective the vaccine is if given in 1 or 2 doses versus the recommended 3.