A new study from the Cincinnati Children's Hospital Medical Center shows the HPV vaccine has helped decrease infection rates in teens, even among those who aren't immunized.

The study is believed to be the first to show a substantial decrease in HPV infection in a community setting.

The researchers noted infection with the types of the human papillomavirus (HPV) covered by the vaccine decreased in vaccinated women by 69%. Two of these HPV types - HPV-16 and HPV-18 - cause about 70% of cervical cancer.

The prevalence of vaccine-type HPV decreased to 13.4% from 31.7%. The decrease was greatest among vaccinated participants, but also was substantial for those who were unvaccinated, at 49%.

Most of the women in the study were young, black women with Medicaid insurance.

The researchers noted it is a relatively small study in a single city and larger studies are needed, but this is a good start.

"The results are promising in that they suggest that vaccine introduction could substantially reduce rates of cervical cancer in this community in the future," Dr. Jessica Kahn said in a release about the study, which was published Monday in the journal Pediatrics.