Despite strong evidence of its effectiveness, few of the young women who are eligible for the human papillomavirus (HPV) vaccine take it, according to research presented at the Ninth Annual AACR Frontiers in Cancer Prevention Research Conference, held Nov. 7-10. What's more, many of the teens who begin treatment do not complete the recommended three-dose regimen.

"Only about one-third of young women who begin the three-dose series actually complete it; this means that large numbers of teenagers are unprotected or under-protected from strains of HPV that lead to cervical cancer," said J. Kathleen Tracy, Ph.D., assistant professor, epidemiology and public health, University of Maryland School of Medicine (UMSOM), Baltimore.

HPV is the most common sexually transmitted disease among adolescent girls in the United States. At any given time, 29.5 percent of sexually active 14- to 19-year-old teenagers are infected. Persistent infection with certain HPV types may lead to cervical cancer.

Tracy and colleagues gathered information from the University of Maryland Medical Center's (UMMC) clinical data repository on the 9,658 teenagers and young women who were eligible for HPV vaccination between August 2006 (when UMMC began offering the vaccine) and August 2010. In all 2,641 young women started HPV vaccination; 39.1 percent received a single dose, 30.1 percent received two doses and 30.78 percent completed the recommended three-dose regimen.

Two-thirds of the teenagers who initiated vaccination were black. Age was a factor in vaccine adherence; young women aged 18 and older were the least likely to take more than a single dose. Young black women and teens were less likely than white to complete the three-dose series.

From a public health perspective, these findings highlight several critical issues, Tracy said. Scientists and public health advocates must identify strategies for increasing vaccination initiation. For instance, practitioners may have to play a more active role in encouraging patients to complete the doses, she said. Parents can be valuable partners, encouraging vaccination and ensuring that their daughters complete all three doses. Finally, strategies are needed to increase completion among all young adult women.

Technology may be one answer. Tracy and her team are preparing to launch a clinical trial to determine whether text message reminders increase completion of the three-dose series.