Immunogenicity and Safety of I-HAV in Healthy Thai Children and Adolescents Lacking Protective Antibody After L-HAV
Immunogenicity and Safety of Inactivated Hepatitis A Vaccine in Healthy Thai Children and Adolescents Lacking Protective Antibody Levels After a Single Dose of Live-attenuated Hepatitis A Vaccine
Chiang Mai University
36 participants
May 25, 2025
INTERVENTIONAL
Conditions
Summary
Hepatitis A virus (HAV) remains a common infection in Thai children. Two HAV vaccines are available: inactivated vaccine (I-HAV, 2 doses) and live-attenuated vaccine (L-HAV, single dose), but neither is included in Thailand's national immunization program. Our previous randomized, active-controlled, open-label, non-inferiority trial trial found that some participants remained seronegative after one L-HAV dose (anti-HAV IgG \<1 S/CO) (preliminary data). This study aims to evaluate the immunogenicity and safety of an additional dose of I-HAV in healthy Thai children and adolescents who did not develop protective antibody levels after a single dose of L-HAV.
Eligibility
Inclusion Criteria4
- 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 Criteria13
- 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
Interested in this trial?
Get notified about updates and connect with the research team.
Interventions
A formaldehyde-inactivated hepatitis A virus (HM175 hepatitis A virus strain) Dose and administration: 0.5 mL intramuscular injection for participants age \<=18 years, and 1.0 mL intramuscular injection for participants age 19 years and above.
Locations(1)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT06978621