EXECUTIVE SUMMARY

A new analysis of national data indicates about half of girls in the United States receive the human papillomavirus (HPV) vaccine at the recommended age.

  • Results of the study indicate just 14% of girls who received the vaccine received the three-part series between ages 11-12 in 2008, with that number increasing to 55% by 2012. Half of the girls surveyed received the vaccine after age 12, figures suggest.
  • Research suggests vaccination could promote unsafe sexual activity among females by lowering perceived risks of acquiring a sexually transmitted infection (STI) or implicitly endorsing sexual activity by 

 A just-published analysis of national data indicates about half of U.S. girls receive the human papillomavirus (HPV) vaccine at the recommended age.1 Results of the study indicate just 14% of girls who received the vaccine received the three-part series between ages 11-12 in 2008, with that number increasing to 55% by 2012. Half of the girls surveyed received the vaccine after age 12, figures suggest.1

The researchers analyzed data from the annual National Immunization Survey of Teens, a survey conducted by the Centers for Disease Control and Prevention (CDC). The CDC data spanned information from 2008 to 2012 on girls’ ages when the vaccine series was started and completed.

“It has been reported in the literature that HPV prevalence increases with each year of age between 14-24 years,” says Mahbubur Rahman, MMBBS, PhD, MPH, who led the research team and is associate professor in the Department of Obstetrics and Gynecology at the University of Texas Medical Branch at Galveston. “Also, the efficacy of the HPV vaccine is highest when it is given before the onset of sexual activity.”

The Advisory Committee on Immunization Practices (ACIP) has recommended that the vaccine be administered at 11-12 years of age before most adolescents become sexually active, notes Rahman. Researchers at the university wanted to determine what percentage of adolescent girls receive the HPV vaccine at the recommended age, based on nationally representative large sample size and provider-verified age of the vaccine recipients. More efforts are needed to increase HPV vaccine uptake among adolescent girls, as only half of them receive this vaccine at the age recommended by ACIP, the researchers conclude.

Research suggests vaccination could promote unsafe sexual activity among females by lowering perceived risks of acquiring a sexually transmitted infection (STI) or implicitly endorsing sexual activity by recognizing the need for the shot.2-3

Receiving the HPV vaccine does not increase rates of STIs in adolescent females, findings from a new study suggest.4

To perform the study, researchers enrolled 21,000 girls who were vaccinated and matched them with 186,000 unvaccinated girls who were the same age, had the same insurance plan, and lived in the same U.S. geographic region. Scientists tracked outcomes for STIs on a quarterly basis for a year before and a year after vaccination.

Analysis of data indicates that in the vaccinated and unvaccinated groups, STIs increased at the same pace as the girls grew older. The vaccinated girls did have slightly higher STI rates before and after vaccination when compared with the unvaccinated group. This finding might have developed because girls choosing to receive the vaccine were more likely to already be sexually active than those choosing not to be vaccinated, researchers state. However, the rate of increase in STIs was identical between vaccinated and unvaccinated females, which suggests that the girls’ sexual behaviors were not altered by the vaccine. Any behaviors resulting in infections that did occur were independent of the vaccine, they conclude.4

Study co-author Seth Seabury, PhD, associate professor of research in the Department of Emergency Medicine at the Los Angeles-based Keck School of Medicine and a fellow in the Leonard D. Schaeffer Center for Health Policy and Economics at the University of Southern California in Los Angeles, said, “If providing girls with the HPV vaccine caused an increase in risky sexual behavior, we would expect to have seen a steeper increase in STI rates in the quarters following administration of the vaccine. We found no such increase, causing us to conclude that there was no association between using the vaccine and unsafe sexual practices.”

Because the HPV vaccine is one of the few medications developed that can prevent cancer, you can reassure parents, physicians, and policymakers that the vaccine does not promote unsafe sexual practices among girls and young women, says study co-author Anupam Jena, MD, PhD, assistant professor of healthcare policy at Harvard Medical School, internist at Massachusetts General Hospital, both in Boston, and faculty research fellow, National Bureau of Economic Research in Cambridge, MA.

With the introduction of the new nine-valent HPV vaccine, remind patients and their parents that the new vaccine covers even more oncogenic HPV strains than the quadrivalent version, says Anita Nelson, MD, professor in the Obstetrics and Gynecology Department at the David Geffen School of Medicine at the University of California in Los Angeles. The Food and Drug Administration approved Merck Sharp & Dohme Corp.’s Gardasil 9 vaccine in December 2014. The new vaccine covers nine HPV types: HPV 6 and HPV 11, the two low-risk types that cause most cases of genital warts, as well as seven high-risk types: HPV 16, 18, 31, 33, 45, 52, and 58.

REFERENCES

  1. Rahman M, McGrath CJ, Hirth JM, et al. Age at HPV vaccine initiation and completion among US adolescent girls: Trend from 2008 to 2012. Vaccine 2015; 33(5):585-587.
  2. Williams K, Forster A, Marlow L, et al. Attitudes towards human papillomavirus vaccination: A qualitative study of vaccinated and unvaccinated girls aged 17-18 years. J Fam Plann Reprod Health Care 2011; 37(1):22-25.
  3. Schuler CL, Reiter PL, Smith JS, et al. Human papillomavirus vaccine and behavioural disinhibition. Sex Transm Infect 2011; 87(4):349-353.
  4. Jena AB, Goldman DP, Seabury SA. Incidence of sexually transmitted infections after human papillomavirus vaccination among adolescent females. JAMA Intern Med 2015; doi:10.1001/jamainternmed.2014.7886.