 The purpose of this study is to gain a better understanding of the bodys response to a human papillomavirus HPV sexually transmitted disease, vaccine and booster shot. The study will also determine factors related to adolescents not following vaccination schedules. The HPV vaccine requires 3 doses shots. Girls sometimes receive the 3 shots at the recommended time and sometimes girls receive the shots at non-recommended times. This study will evaluate if getting the shots at non-recommended times affects the level of protection provided by the vaccine. Participants will include about 1400 girls 9-17 years old receiving a third dose of HPV vaccine from their primary care clinician. The parentlegal guardian of each subject may answer a questionnaire related to the vaccine schedule. Study procedures include: medical history, questionnaires and blood draws. Participants will be involved in the study for about 6 months from time of enrollment. 