Long-Term Immune Persistence After Bivalent HPV Vaccination in Females From Study 311-HPV-1005

NCT07833852 | Enrolling By Invitation

• 1 other identifier: 311-HPV-1005-EXTEND
• Study Type: observational
• Target: 486
• Locations: 1 country
• Sites: 1

Brief Summary

This is a single-center, open-label, prospective observational extension of Study 311-HPV-1005 (NCT04965350). The study follows females who received at least one dose of a bivalent human papillomavirus vaccine containing HPV-16 and HPV-18 L1 virus-like particles in the base study. No vaccine is administered in this extension. Participants in the immunogenicity persistence subset provide blood samples at Months 42 and 66 after the first dose in the base study for measurement of HPV-16 and HPV-18 neutralizing antibodies. Participants eligible for the breakthrough-case cohort are followed for HPV-related cervical disease, including HPV-16- or HPV-18-related cervical intraepithelial neoplasia grade 2 or worse.

Conditions

Human Papillomavirus Infection; Cervical Intraepithelial Neoplasia

Keywords

Bivalent HPV vaccine; immune persistence; neutralizing antibody; long-term follow-up; breakthrough case; CIN2+; Pichia pastoris

Outcome Measures

Primary Outcomes (4)

• Geometric Mean Titer of Neutralizing Antibodies Against HPV-16

  Serum HPV-16 neutralizing antibody titers are measured using a high-throughput pseudovirus-based neutralization assay. The geometric mean titer and 95% confidence interval are summarized overall and by exposure cohort at each time point.

  At Months 42 and 66 after the first dose in the base study

• Geometric Mean Titer of Neutralizing Antibodies Against HPV-18

  Serum HPV-18 neutralizing antibody titers are measured using a high-throughput pseudovirus-based neutralization assay. The geometric mean titer and 95% confidence interval are summarized overall and by exposure cohort at each time point.

  At Months 42 and 66 after the first dose in the base study

• Percentage of Participants Seropositive for Neutralizing Antibodies Against HPV-16

  The percentage of participants with an HPV-16 neutralizing antibody titer at or above the assay cutoff specified in the statistical analysis plan is summarized with an exact 95% confidence interval at each time point.

  At Months 42 and 66 after the first dose in the base study

• Percentage of Participants Seropositive for Neutralizing Antibodies Against HPV-18

  The percentage of participants with an HPV-18 neutralizing antibody titer at or above the assay cutoff specified in the statistical analysis plan is summarized with an exact 95% confidence interval at each time point.

  At Months 42 and 66 after the first dose in the base study

Secondary Outcomes (1)

• Number and Percentage of Participants With HPV-16- and/or HPV-18-Related CIN2+ Breakthrough Cases

  From the first dose in the base study through Month 66 after the first dose

Study Arms (2)

Commercial-Scale Vaccine Cohort

Participants who were assigned in NCT04965350 to receive one of three consecutive commercial-scale lots of the bivalent HPV vaccine on a 0-, 2-, and 6-month schedule. No vaccine is administered in the extension study.

Biological: Recombinant Human Papillomavirus Bivalent (Types 16 and 18) Vaccine (Pichia pastoris)

Clinical-Scale Vaccine Cohort

Participants who were assigned in NCT04965350 to receive the clinical-scale lot of the bivalent HPV vaccine on a 0-, 2-, and 6-month schedule. No vaccine is administered in the extension study.

Biological: Recombinant Human Papillomavirus Bivalent (Types 16 and 18) Vaccine (Pichia pastoris)

Interventions

Recombinant Human Papillomavirus Bivalent (Types 16 and 18) Vaccine (Pichia pastoris) BIOLOGICAL

Historical exposure assigned in the base study: three intramuscular 0.5-mL doses at Months 0, 2, and 6.

Commercial-Scale Vaccine Cohort

Eligibility Criteria

• Age: 12 Years - 34 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Females previously enrolled in the single-center base study 311-HPV-1005 (NCT04965350) at the Mianyang Center for Disease Control and Prevention. The immunogenicity persistence subset comprises participants who completed the three-dose vaccination schedule and had valid neutralizing antibody results at baseline and Month 7. The breakthrough-case cohort comprises participants who received at least one dose of the study vaccine and were at least 18 years of age at extension-study enrollment or became 18 years of age during the extension study.

You may qualify if:

• Previously enrolled in Study 311-HPV-1005 (NCT04965350) at the Mianyang Center for Disease Control and Prevention.
• Received at least one dose of the bivalent HPV vaccine in the base study.
• For the immunogenicity persistence subset: completed all three doses in the base study and had valid neutralizing antibody results before vaccination and one month after the third dose.
• For the breakthrough-case cohort: at least 18 years of age at extension-study enrollment or becoming 18 years of age during the extension study.
• Participant provided written informed consent; for a participant younger than 18 years at extension-study enrollment, the participant and at least one parent or legal guardian provided written informed consent or assent as required.
• Able to understand and comply with the study procedures. Participants in the immunogenicity persistence subset agreed to blood collection at Months 42 and 66. Participants in the breakthrough-case cohort agreed to scheduled remote or site follow-up and to provide relevant HPV- and cervical-disease information.

You may not qualify if:

• Receipt of any other HPV vaccine during Study 311-HPV-1005 or between completion of the base study and enrollment in this extension.
• At a visit involving blood collection, any condition that may interfere with venipuncture, including a platelet count below 20 x 10\^9/L, phlebitis, or hemophilia.
• Any other factor that, in the investigator's judgment, makes the participant unsuitable for the study.

Sponsors & Collaborators

• Shanghai Zerun Biotechnology Co.,Ltd: lead
• Yuxi Zerun Biotechnology Co., Ltd.: collaborator

Study Sites (1)

Mianyang Center for Disease Control and Prevention

Mianyang, Sichuan, China

Location

Related Links

• Related Info

Biospecimen

Retention: SAMPLES WITHOUT DNA

Serum collected at Months 42 and 66 after the first dose in the base study for HPV-16 and HPV-18 neutralizing antibody testing.

MeSH Terms

Conditions

Papillomavirus Infections; Uterine Cervical Dysplasia

Interventions

Vaccines

Condition Hierarchy (Ancestors)

Sexually Transmitted Diseases, Viral; Sexually Transmitted Diseases; Communicable Diseases; Infections; DNA Virus Infections; Virus Diseases; Tumor Virus Infections; Genital Diseases; Urogenital Diseases; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Precancerous Conditions; Neoplasms; Uterine Cervical Diseases; Uterine Diseases; Genital Diseases, Female; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications

Intervention Hierarchy (Ancestors)

Biological Products; Complex Mixtures

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 16, 2026
• First Posted: September 22, 2026
• Study Start: August 30, 2024
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2027
• Last Updated: September 22, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)