Young women who have not been vaccinated against human papillomavirus (HPV) infection have an increased rate of infection with HPV genetic types that are not covered by the currently available vaccine, referred to in the literature as non-vaccine type HPV. A new study that compared the incidence of non-vaccine type HPV infection before and after the introduction of the HPV vaccine found that differences between unvaccinated and vaccinated women themselves were responsible for the increased infections, and not cross protection or genetic type replacement.

• Investigators looked at 3 cross-sectional surveillance studies of teens and young women between the ages of 13 and 26 years to determine the reasons for the increased rate of non-vaccine related HPV infection.
• The analysis found that among females from a health department clinic, older females, and those whose male partners had consistently used condoms in the past 3 months were more likely to be unvaccinated.
• Among females from a teen health center, not being vaccinated was inversely associated with African American race and being covered by Medicaid.