A study published in Lancet Oncology on June 9th, 2015 finds that one dose of the HPV vaccine might be effective for HPV infection prevention. Researchers from the U.S. National Cancer Institute and other organizations reviewed trials that were previously conducted on 24,000 young women. The goal was to estimate how much protection the women were able to receive from different numbers of doses. Vaccine efficacy against incident HPV-16/18 infections for three doses was 77.0% (95% CI 74.7–79.1), two doses was 76.0% (62·0–85·3), and one dose was 85.7% (70.7–93.7). A change in dosage could increase the number of young women vaccinated by reducing the cost of the vaccines.