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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

Status
Active, not recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT07820241
Enrollment
348
Registered
2026-09-15
Start date
2023-03-25
Completion date
2027-12-01
Last updated
2026-09-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Human Papillomavirus Infection

Keywords

Bivalent HPV vaccine, Immune persistence, Neutralizing antibody, Two-dose vaccination schedule, Long-term follow-up, Pichia pastoris

Brief summary

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.

Interventions

BIOLOGICALBivalent Human Papillomavirus Vaccine (Types 16 and 18, Pichia pastoris)

Each 0.5 mL dose contained 40 micrograms of HPV-16 L1 virus-like particles and 20 micrograms of HPV-18 L1 virus-like particles adsorbed to aluminum phosphate. The vaccine was administered only in the base study 311-HPV-1004; no study vaccine is administered in 311-HPV-1004-EXTEND.

Sponsors

Shanghai Zerun Biotechnology Co.,Ltd
Lead SponsorINDUSTRY
Yuxi Zerun Biotechnology Co., Ltd.
CollaboratorUNKNOWN

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
FEMALE
Age
16 Years to 34 Years
Healthy volunteers
Yes

Inclusion criteria

* 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.

Exclusion criteria

* 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. * Long-term use of immunosuppressive agents or

Design outcomes

Primary

MeasureTime frameDescription
Geometric Mean Titer of HPV-16 Neutralizing AntibodiesMonths 84, 108, and 132 after the first dose in the base studyThe geometric mean and two-sided 95% confidence interval of HPV-16 neutralizing antibody titers are summarized separately for each prior-vaccination cohort using the high-throughput pseudovirus-based neutralization assay.
Geometric Mean Titer of HPV-18 Neutralizing AntibodiesMonths 84, 108, and 132 after the first dose in the base studyThe geometric mean and two-sided 95% confidence interval of HPV-18 neutralizing antibody titers are summarized separately for each prior-vaccination cohort using the high-throughput pseudovirus-based neutralization assay.
Seropositivity Rate for HPV-16 Neutralizing AntibodiesMonths 84, 108, and 132 after the first dose in the base studyThe percentage of participants meeting the assay-defined seropositivity threshold for HPV-16 neutralizing antibodies and its exact two-sided 95% confidence interval are summarized separately for each prior-vaccination cohort.
Seropositivity Rate for HPV-18 Neutralizing AntibodiesMonths 84, 108, and 132 after the first dose in the base studyThe percentage of participants meeting the assay-defined seropositivity threshold for HPV-18 neutralizing antibodies and its exact two-sided 95% confidence interval are summarized separately for each prior-vaccination cohort.

Secondary

MeasureTime frameDescription
Geometric Mean Titer of HPV-16 Neutralizing Antibodies in Stored Serum SamplesBefore the first dose on Day 0 and at Months 7, 12, 24, and 36 after the first dose in the base studyThe geometric mean and two-sided 95% confidence interval of HPV-16 neutralizing antibody titers measured using the high-throughput pseudovirus-based neutralization assay are summarized separately for each prior-vaccination cohort using available stored serum samples collected in the base study from participants who subsequently enrolled in the long-term extension study.
Geometric Mean Titer of HPV-18 Neutralizing Antibodies in Stored Serum SamplesBefore the first dose on Day 0 and at Months 7, 12, 24, and 36 after the first dose in the base studyThe geometric mean and two-sided 95% confidence interval of HPV-18 neutralizing antibody titers measured using the high-throughput pseudovirus-based neutralization assay are summarized separately for each prior-vaccination cohort using available stored serum samples collected in the base study from participants who subsequently enrolled in the long-term extension study.
Seropositivity Rate for HPV-16 Neutralizing Antibodies in Stored Serum SamplesBefore the first dose on Day 0 and at Months 7, 12, 24, and 36 after the first dose in the base studyThe percentage of participants meeting the assay-defined seropositivity threshold for HPV-16 neutralizing antibodies and its exact two-sided 95% confidence interval are summarized separately for each prior-vaccination cohort using available stored serum samples collected in the base study from participants who subsequently enrolled in the long-term extension study.
Seropositivity Rate for HPV-18 Neutralizing Antibodies in Stored Serum SamplesBefore the first dose on Day 0 and at Months 7, 12, 24, and 36 after the first dose in the base studyThe percentage of participants meeting the assay-defined seropositivity threshold for HPV-18 neutralizing antibodies and its exact two-sided 95% confidence interval are summarized separately for each prior-vaccination cohort using available stored serum samples collected in the base study from participants who subsequently enrolled in the long-term extension study.

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 18, 2026