How long immunity lasts after inactivated hepatitis A vaccine

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a single-center, open-label observational study led by Sinovac in Changzhou. It will enroll at least 106 healthy adults aged 21–28 who previously completed the PRO-HA-4006 vaccination series. Participants will provide informed consent and have a one-time blood draw (about 3 mL) to measure hepatitis A antibody persistence. Interventions involve the licensed vaccines Healive and Havrix as background exposures. The study aims to characterize how long the immune response from vaccination persists over two decades.

Why it matters

Who can join: the full rules

Inclusion Criteria:

Participants must meet all of the following criteria to be eligible for this study:

1. Healthy participants aged 21-28 years who previously participated in PRO-HA-4006 and completed the full vaccination course;
2. Participants who are able to understand and voluntarily sign the informed consent form;
3. Provision of valid legal identification.

Exclusion Criteria:

Individuals meeting any of the following criteria will be excluded from this study:

1. History of hepatitis A virus infection;
2. Receipt of any vaccine containing hepatitis A antigen since participation in the PRO-HA-4006 clinical study;
3. Autoimmune disease or immunodeficiency/immunosuppression;
4. Coagulation abnormalities, such as coagulation factor deficiency or platelet abnormalities, or a history of significant bleeding, hematoma, or ecchymosis following intramuscular injection or venipuncture;
5. In the investigator's judgment, any other factor that makes the participant unsuitable for participation in the clinical study.

Where it's running

• Changzhou City Center for Disease Control and Prevention
  Changzhou, Jiangsu, China Recruiting

Study contacts

• Principal investigator: Wenguo Xu — Changzhou City Center for Disease Control and Prevention
• Study coordinator: Wenguo Xu
• Email: 853574402@qq.com
• Phone: +86 18912330198

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Community spread of multiple infectious diseases in Cambodia from a One Health perspective

  This project will test how common and connected dengue, chikungunya, Zika, Japanese encephalitis, and West Nile infections are among people, animals, and the environment across Cambodia.

  Recruiting Institut Pasteur du Cambodge · Phnom Penh, Phnom Penh · NCT07358910

• Hepatitis A vaccine study to see how well different doses work in adults and kids

  This Phase 3 study tests two doses of Healive for safety and immune response in adults and children, with adults receiving a single actively treated dose and children randomly receiving Healive or another HepA vaccine.

  Recruiting Phase 3 Sinovac Biotech Co., Ltd · Hanoi · NCT07793227

• Meningococcal vaccine for children 12–23 months old (Group ACYW135)

  This study tests whether the new Group ACYW135 meningococcal vaccine in healthy children aged 12 to 23 months can provoke a similar immune response and has an acceptable safety profile compared with a licensed vaccine.

  Recruiting at 2 sites Phase 3 Sinovac Biotech Co., Ltd · Nanning, Guangxi and 1 other locations · NCT07505836

• Group ACYW135 meningococcal vaccine in children 6-11 months

  This trial tests whether the investigational meningococcal vaccine in healthy infants aged 6 to 11 months can provoke a strong immune response with good safety compared with a licensed vaccine.

  Recruiting at 2 sites Phase 3 Sinovac Biotech Co., Ltd · Nanning, Guangxi and 1 other locations · NCT07505823

• Meningococcal vaccine in infants aged 3-5 months

  This trial tests a new group ACYW135 meningococcal vaccine in healthy babies aged 3 to 5 months to see if it triggers a strong immune response and how safe it is, with a booster given at 12 months.

  Recruiting at 2 sites Phase 3 Sinovac Biotech Co., Ltd · Nanning, Guangxi and 1 other locations · NCT07505810

• Sequential vaccination with Sabin-strain and wild-strain inactivated polio vaccines

  It will test different combinations and injection routes of inactivated polio vaccines in healthy 2-month-old infants to see if they produce strong antibody protection with good safety.

  Recruiting at 3 sites Phase 4 Sinovac Biotech Co., Ltd · Kawit, Cavite and 2 other locations · NCT07457060

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.