This study is exploring if one dose of the HPV vaccine can offer the same immune protection as two or three doses. HPV, or Human Papillomavirus, can cause several types of cancer. The vaccine is crucial because it helps prevent these cancers by creating antibodies, which are proteins that fight infections. Participants will be healthy adults aged 18-45 who have not had the HPV vaccine or infection before. The study involves getting blood samples and checking immune responses in the lymph nodes (small glands that help fight infection) and bone marrow (where blood cells are made).

• The study requires multiple visits for blood tests and other procedures.
• Participants will receive a 1 or 2-dose HPV vaccine and can complete the full series later.
• Participation includes needle procedures in the armpit and hip bone, with some risks.

Understanding if a single-dose vaccine can be effective will help improve vaccination strategies and public health recommendations.