ClinicalTrials.gg
Sign In
RecruitingNCT07889219Updated Oct 22, 2026

Study on the Long-Term Persistence of Immunity Induced by Inactivated Hepatitis A Vaccine

An observational study in Hepatitis A, sponsored by Sinovac Biotech Co., Ltd. Recruiting at 1 site in China. Open to participants aged 21 Years to 28 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-22.

Sponsored by Sinovac Biotech Co., Ltd · Observational

From the registry’s dates

  • Started Aug 2026; still recruiting 2 months later.
Updated Oct 22, 2026Newly registeredGo to Updates ↓
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
106
Ages
21 Years to 28 Years
Sex
All
01

Study summary

This study is a single-center, open-label, controlled study. Its primary objective is to evaluate the 20-year persistence of immunity induced by the inactivated hepatitis A vaccine. At least 106 healthy participants aged 21-28 years will be enrolled. Participants will be selected from individuals who completed the full vaccination course in the PRO-HA-4006 clinical study (Three-Batch Consistency Study of Healive® in Healthy Children Aged 1-8 Years in Changzhou) . After voluntarily providing informed consent, each participant will undergo one venous blood collection of approximately 3.0 mL for hepatitis A antibody testing to assess the persistence of immunity induced by the hepatitis A vaccine.

02

Conditions studied

  • Hepatitis A

Browse trials for

Keywords

  • Hepatitis A
  • Inactivated hepatitis A vaccine
  • Immune persistence
03

In context

Hepatitis A

2,698 studies on the registry are indexed under Hepatitis A; 137 are open to participants now.

This study's planned enrollment of 106 is below the median of 250 across 686 observational studies indexed under Hepatitis A.

Browse Hepatitis A studies →

Lead sponsor

Sinovac Biotech Co., Ltd is the lead sponsor of 93 studies on the registry; 19 are open to participants now.

Browse Sinovac Biotech Co., Ltd studies →

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
21 Years to 28 Years
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

Healthy participants who received two doses of inactivated hepatitis A vaccine in the PRO-HA-4006 trial and were included in the study, aged 21 to 28 years at enrollment.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Participants must meet all of the following criteria to be eligible for this study:

  1. Healthy participants aged 21-28 years who previously participated in PRO-HA-4006 and completed the full vaccination course;
  2. Participants who are able to understand and voluntarily sign the informed consent form;
  3. Provision of valid legal identification.

Exclusion criteria

Exclusion Criteria:

Individuals meeting any of the following criteria will be excluded from this study:

  1. History of hepatitis A virus infection;
  2. Receipt of any vaccine containing hepatitis A antigen since participation in the PRO-HA-4006 clinical study;
  3. Autoimmune disease or immunodeficiency/immunosuppression;
  4. Coagulation abnormalities, such as coagulation factor deficiency or platelet abnormalities, or a history of significant bleeding, hematoma, or ecchymosis following intramuscular injection or venipuncture;
  5. In the investigator's judgment, any other factor that makes the participant unsuitable for participation in the clinical study.
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
106 participants (estimated)
Patient registry
No

Groups and cohorts

  • Trial group

    Participants received two doses of inactivated hepatitis A vaccine, Healive® in the PRO-HA-4006 trial.

    Biological: Healive®

  • Control group

    Participants received two doses inactivated hepatitis A vaccine, Havrix® in the PRO-HA-4006 trial.

    Biological: Havrix®

Interventions

  • BiologicalHealive®

    Healive® developed by Sinovac Biotech Co., Ltd, per dose containing 250 u antigen, two doses administered in the prior trial.

  • BiologicalHavrix®

    The control vaccine (0.5 mL/dose) contained 720 ELISA units (El.U) antigen and 0.25 mg alum with 2-phenoxyethanol as preservative.

06

What researchers measure

Primary outcomes

  1. Seropositivity rate and geometric mean concentration (GMC) of hepatitis A antibodies at Year 20 after vaccination.

    Evaluate the immune persistence of anti-HAV antibodies in serum 20 years after two doses of inactivated hepatitis A vaccine. Seropositivity is defined as anti-HAV antibody concentration ≥ 20 mIU/mL.

    Time frame: 20 years after vaccination

07

Study locations

1 of 1 sites recruiting
  • Changzhou City Center for Disease Control and Prevention
    Changzhou, Jiangsu, China
    Recruiting
08

References and documents

Individual participant data

Plan to share: Undecided

No publications or documents are linked to this record.

09

Timeline

1 registry update since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Aug 2026 (actual). Primary completion is estimated for Nov 2026, 3 months after the start.

Of 65 industry-sponsored observational studies under Hepatitis A, half reached primary completion within 27 months of starting (the median), counting those still running; a quarter within 16 and three quarters within 45. This study's planned 3 months is below that.

Counting every sponsor, half of 215 studies reached it within 32 months; a quarter within 17 and three quarters within 60.

How these figures are worked out, and which studies are left out of them.

Registered
Oct 15, 2026
First posted
Oct 22, 2026
StartActual
Aug 2, 2026
Primary completionEst.
Nov 30, 2026
CompletionEst.
Nov 30, 2026
Last update
Oct 22, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
Registered
First appeared on the registry. No changes since
Oct 22, 2026
Show all 1 update
  1. Oct 22, 2026
    First appeared on the registry

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT07889219
Lead sponsor
Sinovac Biotech Co., Ltd
Collaborators
Changzhou Center for Disease Control and Prevention
Responsible party
Sponsor
First posted
Oct 22, 2026
Start date
Aug 2, 2026
Primary completion
Nov 30, 2026 (estimated)
Completion
Nov 30, 2026 (estimated)
Last update
Oct 22, 2026

Study contacts

Wenguo Xu
Contact
853574402@qq.com
+86 18912330198
Wenguo Xu
principal investigator · Changzhou City Center for Disease Control and Prevention

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Interested in this study?

Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.

Contact study team

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Other studies in this condition

Hepatitis A →

Other studies from this sponsor

Sinovac Biotech Co., Ltd →

Start the discussion