Additional Study Information: The main purpose of this study is to: Find out if the study vaccine therapies cause any side effects (unexpected or unwanted reactions) and how well they are tolerated in women with persistent HPV types 16 or 18 infection of the cervix. Find out whether your body responds (the immune response). Compare the effects (both good and bad) of the study vaccines to those of the placebo injections. The placebo given in this study will consist of saline (sterile salt water) and looks just like the study vaccines and is given the same way, but has no active vaccine in it. Since it is a study, the outcome might be that the vaccines do not work as expected or produce unexpected harms for participants. You might not benefit directly from taking these vaccines. However, information learned from you and others in this study will contribute to scientific knowledge, and help in the development of new ways to treat persistent HPV infections.