NCT07820241Active, not recruiting
Long-term Immune Persistence of a Bivalent HPV Vaccine in Females From Study 311-HPV-1004
An Open-label, Long-term Extension Study to Evaluate the Persistence of Immune Responses to a Bivalent Human Papillomavirus Vaccine (Pichia Pastoris) in Healthy Females Who Were Aged 9 to 26 Years at Enrollment in Study 311-HPV-1004
Source: ClinicalTrials.gov · Last updated 17 Sept 2026
Brief summary (registry, in English)
This long-term extension study evaluates the persistence of neutralizing antibody responses to a bivalent human papillomavirus vaccine in females who previously participated in study 311-HPV-1004 (NCT02740777). Participants belonged to one of three vaccination cohorts in the base study: adolescents who received two doses at Months 0 and 6, adolescents who received three doses at Months 0, 2, and 6, and adults who received three doses at Months 0, 2, and 6. No vaccine is administered in the extension study. Blood samples are collected at Months 84, 108, and 132 after the first dose in the base study and tested for HPV-16 and HPV-18 neutralizing antibodies using a high-throughput pseudovirus-based neutralization assay.
- Status (registry)
- Active, not recruiting
- Study type
- Observational
- Enrollment
- 348 (actual)
- First submitted
- 10 Sept 2026
- Start date
- 25 Mar 2023
- Primary completion date
- 30 Apr 2027
- Lead sponsor
- Shanghai Zerun Biotechnology Co.,Ltd
- NCT number
- NCT07820241
What you commit to
- Study type: Observational
- Participants enrolled: 348
- From 25 Mar 2023 to the primary completion date, 30 Apr 2027
- 2 sites in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Receipt of any HPV vaccine other than the study vaccine during study 311-HPV-1004 or between completion of that study and enrollment in this extension study.
- Use of an investigational or unregistered product, other than the study vaccine, during study 311-HPV-1004 or between completion of that study and enrollment in this extension study.
- Seropositivity for both HPV-16 and HPV-18 antibodies at baseline in study 311-HPV-1004.
Other
- Long-term use of immunosuppressive agents or
Who the study is looking for
- The participant, and the participant's legal guardian when applicable, is able to understand the study information and voluntarily sign the informed consent form for the extension study.
- In the investigator's judgment, the participant is able to comply with protocol requirements, including attending scheduled visits and responding to follow-up telephone contacts.
- The participant was enrolled in study 311-HPV-1004 and completed blood collection at Day 0 and Months 7, 12, 24, and 36.
Age in the registry: 16 years to 34 years · Sex: Female · Accepts healthy volunteers
Sites (2)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Zhongshan County Center for Disease Control and Prevention Coordinator of this site? Confirm its status | Hezhou | China | Unknown status |
| Hezhou Center for Disease Control and Prevention Coordinator of this site? Confirm its status | Hezhou | China | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.