Hepatitis ANCT07032610
Long-term Immunogenicity of L-HAV Vaccine Among Healthy Thai Children and Adolescents
An observational study of Hepatitis A and Hepatitis A Virus, run by Chiang Mai University at 1 site in Thailand.
Trial 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). Read more about this study
- Who is it for?
- Ages 18 months to 20 yearsHealthy volunteers can take part
- Conditions the study is for
- Hepatitis A, Hepatitis A Virus, Vaccine-Preventable Diseases
- How many people
- 60 participants
- Where
- 1 siteThailand
- Study dates
- 26 Jun 2025to 31 Jul 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 months to 20 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Study population: Healthy Thai children and adolescents age 18 months to 20 years who received a single dose of L-HAV vaccine in the previous RCT study.
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
Thailand1 site
Department of Pediatrics, Faculty of Medicine, Chiang Mai University
Chiang Mai, 50200
About this study
Official title: Long-term Immunogenicity of Lived-attenuated Hepatitis A Virus Vaccine Among Healthy Thai Children and Adolescents
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.
Read the 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
- Keywords
- Live-attenuated hepatitis A vaccine, Immunogenicity, Seropositive rate
- Medical subject headings
- Hepatitis A, Hepatitis, Vaccine-Preventable Diseases
What is being measured
The primary outcome is the main question the study is designed to answer.
Anti-HAV seropositivity rate
Anti-HAV seropositivity rate following a single L-HAV vaccine
Measured: 1 year after L-HAV vaccination
Anti-HAV antibody level
Geometric mean concentration (GMC) of anti-HAV antibodies following a single L-HAV vaccine
Measured: 1 year after L-HAV vaccination
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jun 2025
- Study start26 Jun 2025
- Primary completion28 Jun 2025
- Study completion31 Jul 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Hepatitis AStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chiang Mai University
- Sponsor type
- University, hospital or other
- Collaborators
- Faculty of Medicine, Chiang Mai University
- Responsible party
- Principal investigator, Tavitiya Sudjaritruk, Chiang Mai University
- Investigators
- Tavitiya Sudjaritruk, MD, PhD, Study chair, Department of Pediatrics, Faculty of Medicine, Chiang Mai UniversityNatchaya Kunanitthaworn, MD, Principal investigator, Department of Pediatrics, Faculty of Medicine, Chiang Mai University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07032610
- Sponsor's protocol ID
- PED-2568-0420
- Status last verified
- May 2026
- First submitted
- 16 Jun 2025
- Last updated
- 22 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: There is not a plan to make individual participant data (IPD) available to other researchers for this study.
Publications
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.
PubMed 27345175Liu 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.
PubMed 23571173Kunanitthaworn 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.
PubMed 37833325
Study at a glance
From the registry record, last updated by the sponsor on 22 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Long-term Immunogenicity of Lived-attenuated Hepatitis A Virus Vaccine Among Healthy Thai Children and Adolescents
- ClinicalTrials.gov ID
- NCT07032610
- Acronym / sponsor ID
- PED-2568-0420
- Conditions
- Hepatitis A, Hepatitis A Virus, Vaccine-Preventable Diseases
- Keywords
- Live-attenuated hepatitis A vaccine, Immunogenicity, Seropositive rate
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Chiang Mai UniversityUniversity, hospital or other
- Collaborators
- Faculty of Medicine, Chiang Mai University
- Study start
- 26 Jun 2025 (actual)
- Primary completion
- 28 Jun 2025 (actual)
- Study completion
- 31 Jul 2026 (estimated)
- First posted
- 24 Jun 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Observational model
- Case only
- Time perspective
- Cross-sectional
Who may qualify
- Ages
- 18 months to 20 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
- Study population
- Healthy Thai children and adolescents age 18 months to 20 years who received a single dose of L-HAV vaccine in the previous RCT study.
Key inclusion criteria (3 listed)
- 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
Key exclusion criteria (5 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Anti-HAV seropositivity rate
Time frame: 1 year after L-HAV vaccination
Anti-HAV seropositivity rate following a single L-HAV vaccine
Anti-HAV antibody level
Time frame: 1 year after L-HAV vaccination
Geometric mean concentration (GMC) of anti-HAV antibodies following a single L-HAV vaccine
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 May 2026.
- Background: PubMed 27345175Ma 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.
- Background: PubMed 23571173Liu 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.
- Results publication: PubMed 37833325Kunanitthaworn 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.
- Individual participant dataSharing planned: No. There is not a plan to make individual participant data (IPD) available to other researchers for this study.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tavitiya Sudjaritruk, MD, PhD study chair
Department of Pediatrics, Faculty of Medicine, Chiang Mai University
Natchaya Kunanitthaworn, MD principal investigator
Department of Pediatrics, Faculty of Medicine, Chiang Mai University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Hepatitis A and Hepatitis A Virus, run by Chiang Mai University at 1 site in Thailand.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 22 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Thailand. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Anti-HAV seropositivity rate (time frame: 1 year after L-HAV vaccination). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07032610, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 May 2026.