Immunogenicity and Safety of Sequential 2vHPV-9vHPV Vaccination in Girls Aged 9-14 Years

Inclusion Criteria * Have not received any HPV vaccine products. * Girls aged 9 to 14 years. * Reside permanently at the research site. Both the participant and her legal guardian have voluntarily agreed to participate, have signed the informed consent form, understand and agree to comply with the study protocol, and are able to complete all scheduled blood collections and follow-up visits. Exclusion Criteria * Suspected or confirmed fever (≥38.5°C) within 72 hours prior to enrollment, or axillary temperature \>37.0°C on the day of enrollment. * HIV infection or other immunocompromising conditions. * Presence of acute illness or being in the acute phase of a chronic disease. * History of severe allergic reactions to any component of the study vaccine or to previous vaccinations. * Contraindications to intramuscular injection, such as thrombocytopenia, coagulation disorders, or current anticoagulant therapy. * Receipt of non-live vaccines within 14 days or live attenuated vaccines within 28 days prior to HPV vaccination in this study. * Receipt of blood or blood-derived products within 3 months prior to enrollment, or planned use within 6 months from the first vaccination to completion of the full vaccination schedule. * Any disease or condition deemed by the investigator to place the participant at unacceptable risk, prevent adherence to study requirements, or interfere with the assessment of vaccine responses.