A 20-Year Study of the Persistence of Immunity in Healthy Children Aged 1-8 Years Induced by Inactivated Hepatitis A Vaccine
Sponsor study identifier
observational
106
1 country
1
Study Start
August 2, 2026
Actual (reported)Primary Completion
November 30, 2026
EstimatedPlanned date reported by the registry; this milestone is not confirmed as achieved.
Study Completion
November 30, 2026
EstimatedPlanned date reported by the registry; this milestone is not confirmed as achieved.
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.
Registry-reported information. Elapsed time and enrollment totals alone do not measure study progress or recruitment pace.
November 30, 2026
EstimatedPlanned date reported by the registry; this milestone is not confirmed as achieved.
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Dates and qualifiers reported by the registry. Estimated dates do not confirm that a milestone has occurred.
August 2, 2026
Actual (reported)October 15, 2026
Actual (reported)October 22, 2026
Actual (reported)November 30, 2026
EstimatedPlanned date reported by the registry; this milestone is not confirmed as achieved.
November 30, 2026
EstimatedPlanned date reported by the registry; this milestone is not confirmed as achieved.
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.
20 years after vaccination
Participants received two doses of inactivated hepatitis A vaccine, Healive® in the PRO-HA-4006 trial.
Participants received two doses inactivated hepatitis A vaccine, Havrix® in the PRO-HA-4006 trial.
Healive® developed by Sinovac Biotech Co., Ltd, per dose containing 250 u antigen, two doses administered in the prior trial.
The control vaccine (0.5 mL/dose) contained 720 ELISA units (El.U) antigen and 0.25 mg alum with 2-phenoxyethanol as preservative.
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.
Changzhou City Center for Disease Control and Prevention
Changzhou, Jiangsu, China
Wenguo Xu
Changzhou City Center for Disease Control and Prevention
First Submitted
October 15, 2026
First Posted
October 22, 2026
Study Start
August 2, 2026
Actual (reported)Primary Completion
November 30, 2026
EstimatedPlanned date reported by the registry; this milestone is not confirmed as achieved.
Registry-reported names are shown in full. Names without a link have not yet been matched to a Syfrah profile.
Contact the study team to confirm eligibility.
Study Completion
November 30, 2026
EstimatedPlanned date reported by the registry; this milestone is not confirmed as achieved.
Last Updated
October 22, 2026
Record last verified: 2026-10
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Source: ClinicalTrials.gov.
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