Recent experience with HPV vaccine implementation in low resource settings has suggested that high vaccine coverage for all three doses could be achieved provided programs are planned well and have full and complementary components in place. However, some locations experienced substantial rates of partially vaccinated girls, those who received only one or two doses. From the vaccine trial data published thus far, we know that the vaccines produce high levels of type-specific anti-HPV antibodies which begin to stabilize past 24 months post-vaccination. Without an immune correlate of protection, it is difficult to know whether girls who received one or two vaccine doses will still experience the same benefit of protection from HPV infection as those who received all three doses of vaccine.