Published Nov. 15, 2016
Clinical Infectious Diseases
Introduction of the human papillomavirus (HPV) vaccine 11 years ago not only produced a dramatic drop in HPV infections in vaccinated young women, but also led to herd protection in the broader community of unvaccinated women.
A study led by Jessica Kahn, MD, MPH, tracked vaccination rates and HPV infection rates among 1,180 girls and women ages 13-26 every three years from 2006 to 2014. All were patients at Cincinnati Children’s Teen Health Center or the Cincinnati Health Department.
HPV infections are linked to cervical cancer, the third-most common cancer and fourth-leading cause of cancer death in women worldwide.
As vaccination rates increased from zero to 71.3 percent during the study, the prevalence of vaccine-type HPV decreased by 90.8 percent in vaccinated young women, demonstrating high effectiveness in a community setting. The prevalence of vaccine-type HPV also decreased by 32.3 percent in unvaccinated women, providing evidence of herd protection.
Study participants were all sexually experienced, making the findings of high vaccine effectiveness even more remarkable.
“Determining the herd-protective effects of HPV vaccines is important not only because it provides key information about the total health impact of vaccination but also because it provides necessary data to assess vaccine cost-effectiveness,” Kahn says. “Although long-term surveillance will be important, the results of the study suggest that vaccination programs could have a substantial population-level impact on rates of HPV-related cancers.”