Booster shot hope: extra hepatitis a vaccine studied for thai kids
NCT ID NCT06978621
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study looks at whether a second, inactivated hepatitis A vaccine can safely boost protection in healthy Thai children and teens who did not develop enough antibodies after a single dose of a live-attenuated hepatitis A vaccine. About 36 participants who took part in an earlier trial will receive one extra shot. Researchers will check antibody levels and watch for side effects to see if the booster works.
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Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 3
Large-scale testing in a bigger group. Usually the last step before a treatment can be approved.
- Participants
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About 36 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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May 2025
- Expected to finish
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Jul 2026
An estimate. End dates often move.
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 months to 20 years
- Sex
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Anyone
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
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 (+/- 2 months) * Have not demonstrate a seropositivity against HAV (anti-HAV IgG \<1 S/CO) at 1 month after L-HAV vaccination * 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 * Has underlying conditions including thrombocytopenia, coagulopathy, hemophilia A or B, neurological disorders, immunodeficiency disorders, chronic liver disease, or chronic hepatitis B or C infection * Has received immunosuppressive agents, immunomodulatory agents, or high-dose corticosteroids (greater than 2 mg/kg/day or more than 20 mg/day) for more than 14 consecutive days within 6 months prior to study enrollment * Has received blood products or blood components, including immunoglobulins, within 6 months prior to study enrollment * Has received other live vaccines within 30 days prior to study enrollment * Has history of allergy to vaccines or any vaccine components, such as aluminum hydroxide, 2-phenoxyethanol, neomycin, formaldehyde, or gentamicin sulfate, or has history of severe allergic reactions (e.g., anaphylaxis) to any vaccines * Women planning for pregnancy, pregnant women or lactating women * Women in childbearing age who cannot use contraceptive methods during study participation * Is concurrently involved in other clinical trials in which receiving an investigational vaccine or study drug as part of study participation * Have any condition that, in the opinion of the site investigator, would compromise the subject's ability to participate in the study
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Department of Pediatrics, Faculty of Medicine, Chiang Mai University
Chiang Mai, 50200, Thailand
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Other studies related to the condition(s) this trial covers.
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