Complete HPV Immunization Rates Low in the United States

Emma Hitt, PhD

March 12, 2010

March 12, 2010 (Atlanta, Georgia) — Although 25% of adolescents 13 to 17 years old reported receiving at least 1 dose of the quadrivalent human papillomavirus (HPV) vaccine, only 11% reported receiving all 3 doses, according to new research from the US Centers for Disease Control and Prevention (CDC), which was presented during a late-breaking session here at the 2010 National STD Prevention Conference.

According to the researchers, the 3 most common barriers to vaccination reported by parents were the belief that the child did not need the vaccine, a lack of sufficient vaccine knowledge, and the fact that the child was not sexually active.

Charlene Wong, a fourth year medical student at Emory University School of Medicine in Atlanta, Georgia, and a research fellow in the Division of Cancer Prevention and Control at CDC, presented her team's findings.

In 2006, the Advisory Committee on Immunization Practices (ACIP) recommended quadrivalent HPV vaccine (types 6, 11, 16, and 18) (Gardasil, Merck) in the United States for routine immunization of 11- and 12-year-old girls. The first dose can be given to girls as young as 9 years, with catch-up vaccinations through to age 26. Similar recommendations were made by the ACIP in 2009 for the more recently approved bivalent HPV vaccine (types 16 and 18) (Cervarix; GlaxoSmithKline).

The latest recommendations state that the 2 vaccines can be used interchangeably to complete the 3-dose series, but that using the same vaccine for all 3 doses is optimal.

To estimate the vaccine uptake, data were collected from the National Health Interview Survey 2008. The survey included 2205 households with a female child aged 9 to 17 years (age 9 and 10 years, n = 439; age 11 and 12 years, n = 428; age 13 to 17 years, n = 1338).

Parents were asked a series of questions, including whether the child received the vaccine (parent recall), the number of shots received (parent recall), and the reason the child did not receive the vaccine.

Overall, 15% (95% confidence interval [CI], 11.1 - 19.7%) of 11 and 12 year olds and 25% (95% CI, 22.6 - 28.5%) of 13 to 17 year olds had received at least 1 dose of HPV vaccine.

By comparison, 10% of 11 and 12 year olds and 18% of 13 to 17 year olds received a second dose. Only 6% and 11%, respectively, received the third dose at the time of the survey.

"Although approximately 40% of girls who initiated vaccination completed the series, interventions are needed to increase the number of patients receiving all 3 doses," Ms. Wong told Medscape Infectious Diseases. There are currently no data on the effectiveness of fewer than 3 doses.

According to Ms. Wong, providers should strongly recommend HPV vaccination for 11- and 12-year-old girls. "In addition to being immunized as part of the adolescent vaccination platform, girls vaccinated prior to the onset of sexual activity and potential exposure to HPV will gain the greatest protection from vaccination," she said.

She also stated that "because the HPV vaccine has the potential to prevent up to 70% of cervical cancer cases, and also prevents other diseases associated with HPV, our findings emphasize the need for providers and parents to help girls start and complete all HPV vaccine doses as recommended for them."

"We are just not very good at giving adolescent vaccines in this country," said conference attendee Susan Rosenthal, PhD, pediatric psychologist and researcher in the area of adolescent health, promotion of sexual health, and vaccine acceptability at Columbia University in New York City.

According to Dr. Rosenthal, the rate of uptake for the HPV vaccine is about comparable to that of the meningococcal vaccine. "This country relies on school mandates to get high uptake of vaccines," she told Medscape Infectious Diseases.

"In the case where we have no school mandate or a weak school mandate (such as with HPV), we don't do a very good job of immunizing our children," she said.

Dr. Rosenthal suggests that one of the main reasons that the rates are low is that "this is a new vaccine that people are unfamiliar with, and there is a fairly substantial antivaccine lobby in this country."

The study was supported by funds from the CDC. The findings and conclusions in this presentation are those of the authors and do not necessarily represent the official position of the CDC. Ms. Wong and Dr. Rosenthal have disclosed no relevant financial relationships.

2010 National STD Prevention Conference (NSTDP): Abstract LBb. Presented March 10, 2010.


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