Long-term Immunogenicity of L-HAV Vaccine Among Healthy Thai Children and Adolescents

NCT ID: NCT07032610

Last Updated: 2025-06-24

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Total Enrollment: 60 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2025-06-22
• Study Completion Date: 2025-09-30

Brief Summary

Hepatitis A virus (HAV) remains a common infection among Thai children. Two types of HAV vaccines are available in Thailand: an inactivated vaccine (I-HAV, administered in two doses 6 months apart) and a live-attenuated vaccine (L-HAV, administered as a single dose). However, neither vaccine is currently included in Thailand's Expanded Programme on Immunization (EPI). In 2024, a randomized, active-controlled, open-label, non-inferiority trial was conducted to compare the immunogenicity and safety of the two-dose I-HAV with the single-dose L-HAV in healthy Thai children and adolescents aged 18 months to 18 years. This study aims to evaluate the long-term seropositive rate and immunogenicity of anti-HAV antibodies in this population following a single dose of L-HAV.

Detailed Description

Hepatitis A virus (HAV) infection remains one of the most common causes of viral hepatitis among children and adolescents in developing countries, including Thailand. The virus is primarily transmitted through the ingestion of contaminated food or water, or through direct contact with an infected person. HAV typically causes acute hepatitis, ranging from mild illness to severe fulminant hepatitis (acute liver failure), but it does not lead to chronic liver disease. Vaccination is a highly effective strategy to prevent HAV infection and its serious complications.

Currently, two types of HAV vaccines are available in Thailand: (1) the inactivated HAV vaccine (I-HAV), which is administered in two doses six months apart and is approved for use in children aged 12 months and older; and (2) the live-attenuated HAV vaccine (L-HAV), administered as a single dose and approved for children aged 18 months and older. However, neither vaccine has been included in Thailand's Expanded Programme on Immunization (EPI), resulting in suboptimal vaccination coverage across the country.

In 2024, the investigators conducted a randomized, active-controlled, open-label, non-inferiority trial to compare the immunogenicity and safety of the two-dose I-HAV regimen with the single-dose L-HAV in healthy Thai children and adolescents aged 18 months to 18 years. The present study aims to assess the long-term seropositive rate and immunogenicity of anti-HAV antibodies among these participants following a single dose of L-HAV.

Conditions

Hepatitis A; Hepatitis A Virus; Vaccine-Preventable Diseases

Study Design

• Observational Model Type: CASE_ONLY
• Study Time Perspective: CROSS_SECTIONAL

Eligibility Criteria

Inclusion Criteria

• Thai children and adolescents who previously participated in the previous RCT study
• Previously randomized to receive one dose of L-HAV vaccine within the past 1 year (+/- 3 months)
• Participants and/or caregivers gives written inform consent/assent form

Exclusion Criteria

• History of acute illness within 4 weeks prior to study enrollment
• Has a history of illness or a diagnosis consistent with hepatitis A after receiving the live attenuated hepatitis A vaccine as part of participation in a previous research study
• Has a history of receiving any additional hepatitis A vaccine after participating in the previous research study
• Presence of fever (body temperature ≥38.0°C), jaundice, or yellowing of the eyes within 4 weeks prior to study enrollment
• Have any condition that, in the opinion of the site investigator, would compromise the subject's ability to participate in the study

• Minimum Eligible Age: 18 Months
• Maximum Eligible Age: 20 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Faculty of Medicine, Chiang Mai University

UNKNOWN

Sponsor Role: collaborator

Chiang Mai University

OTHER

Sponsor Role: lead

Responsible Party

Tavitiya Sudjaritruk

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Tavitiya Sudjaritruk, MD, PhD

Role: STUDY_CHAIR

Department of Pediatrics, Faculty of Medicine, Chiang Mai University

Natchaya Kunanitthaworn, MD

Role: PRINCIPAL_INVESTIGATOR

Department of Pediatrics, Faculty of Medicine, Chiang Mai University

Locations

Department of Pediatrics, Faculty of Medicine, Chiang Mai University

Chiang Mai, , Thailand

Countries

Thailand

Central Contacts

Tavitiya Sudjaritruk, MD, PhD

Role: CONTACT

tavitiya.s@cmu.ac.th

+66-53-936471

Natchaya Kunanitthaworn, MD

Role: CONTACT

natchaya.k@cmu.ac.th

+66-53-936461

Facility Contacts

Tavitiya Sudjaritruk, MD, PhD

Role: primary

tavitiya.s@cmu.ac.th

+66-53-93-6471

References

Ma F, Yang J, Kang G, Sun Q, Lu P, Zhao Y, Wang Z, Luo J, Wang Z. Comparison of the safety and immunogenicity of live attenuated and inactivated hepatitis A vaccine in healthy Chinese children aged 18 months to 16 years: results from a randomized, parallel controlled, phase IV study. Clin Microbiol Infect. 2016 Sep;22(9):811.e9-811.e15. doi: 10.1016/j.cmi.2016.06.004. Epub 2016 Jun 23.

Reference Type: BACKGROUND

PMID: 27345175 (View on PubMed)

Liu XE, Wushouer F, Gou A, Kuerban M, Li X, Sun Y, Zhang J, Liu Y, Li J, Zhuang H. Comparison of immunogenicity between inactivated and live attenuated hepatitis A vaccines: a single-blind, randomized, parallel-group clinical trial among children in Xinjiang Uighur Autonomous Region, China. Hum Vaccin Immunother. 2013 Jul;9(7):1460-5. doi: 10.4161/hv.24366. Epub 2013 Apr 9.

Reference Type: BACKGROUND

PMID: 23571173 (View on PubMed)

Kunanitthaworn N, Mueangmo O, Saheng J, Wongjak W, Lertsiriladakul T, Chaito T, Nantarat P, Sudjaritruk T. Seroprevalence of hepatitis A virus antibodies among children and adolescents living in Northern Thailand: an implication for hepatitis A immunization. Sci Rep. 2023 Oct 13;13(1):17432. doi: 10.1038/s41598-023-44643-0.

Reference Type: RESULT

PMID: 37833325 (View on PubMed)

Other Identifiers

PED-2568-0420

Identifier Type: -

Identifier Source: org_study_id