Decreased prevalence of HPV among vaccinated young females

1. There was a significant decline noted in the prevalence of the human papillomavirus (HPV) types 6, 11, 16, and 18 (those found in the quadrivalent HPV vaccine) among women ages 14 to 24 years between the pre- and post-vaccine time periods.

2. The prevalence of these quadrivalent HPV types (4vHPV) was lower in vaccinated women (those receiving at least 1 dose) compared to those who were unvaccinated.

Evidence Rating Level: 2 (Good)           

Study Rundown: Routine vaccination with the HPV vaccine has been recommended for girls and women ages 12 through 26 years, since 2006. Although vaccine coverage remains relatively low, rates continue to increase. Vaccinating against strains 6, 11, 16, and 18 (4vHPV) has the potential to vastly decrease the prevalence of cervical cancer and genital warts. As such, monitoring the prevalence and efficacy of HPV vaccination remains a public health priority. Through the use of national survey data, this study evaluated pre- and post-vaccination era data to determine the prevalence of HPV strains, including 4vHPV and the 5 additional strains covered by the newer 9-valent HPV vaccine. Approximately half of all females 14 to 19 years, and almost a third of women ages 20 to 24 years, received at least 1 dose of 4vHPV vaccine in the post-vaccine era. Among both age groups, there was a statistically significant decline in 4vHPV prevalence compared to the pre-vaccine era. It was noted that over this time period, a larger proportion of women reported having 3 or more lifetime sexual partners, but HPV prevalence continued to decline. Vaccinated women had significantly lower rates of 4vHPV prevalence compared to those who had not been vaccinated. There was no change in 4vHPV prevalence among unvaccinated women compared to the pre-vaccine era. This study adds to previous evaluation of the HPV vaccine, further establishing the value in offering HPV vaccination per existing guidelines. While this study highlights the benefits of vaccination, it is limited by the self-reported nature of the survey.

Click to read the study published today in Pediatrics

Relevant Reading: Assessment of herd immunity and cross-protection after a human papillomavirus vaccination programme in Australia: a repeat cross-sectional study

Study Author, Dr. Lauri E. Markowitz, MD, talks to 2 Minute Medicine: Division of STD Prevention, National Center for HIV/AIDS, Vital Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia.

“This study provides further evidence that HPV vaccination is reducing the prevalence of HPV infections in the U.S. We have a safe, effective vaccine that can prevent cancer, and that’s an important message to educate people about because not enough children are getting vaccinated with HPV vaccine.”

In-Depth [retrospective cohort]: Using data from the Centers for Disease Control National Health and Nutritional Examination Survey (NHANES), this study included females ages 14 to 34 years from the pre-vaccine era (2003-2006) and the post-vaccine era (2009-2012). Information was collected via computer-based interviews, and cervicovaginal samples were self-collected and submitted by participants. In the post-vaccine era, 51.2% of women 14 to 19 years old and 32.6% of 20 to 24 year old women received at least 1 HPV vaccine dose. Over the studied time period, the percentage of women aged 14 to 24 years reporting at least 3 lifetime sexual partners increased from 58.4% to 67.7%. There was a statistically significant decrease in 4vHPV prevalence among 14- to 19- and 20- to 24-year-olds in the post-vaccine era (11.5% to 4.3%, p < .05, and 18.5% to 12.1%, p < .05, respectively).  There were no significant changes in the prevalence of the 5 additional HPV strains covered by the 9-valent HPV vaccine. Among sexually active women who were vaccinated, 4vHPV prevalence significantly decreased from 18.6% to 2.1%. There was no statistically significant decrease in 4vHPV among unvaccinated women over this time period (18.6% vs 16.9%).

Image: PD

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