The Immune Responses After Hepatitis B Revaccination Doses in a Young Cohort

Study Overview
=================
Brief Summary
-----------------
This prospective cohort study aims to provide the evidence-based clinical guide to help decide the revaccination doses of hepatitis B vaccine that the high-risk young adults without hepatitis B seroprotective antibodies (anti-HBs titer<10 mIU/mL) need to take.

Detailed Description
-----------------
Purpose For young adults born after the neonatal hepatitis B immunization program, especially those who were 20-33 years old after 1987, additional hepatitis B vaccination may have the benefit of strengthening protection from acute hepatitis B infection among high-risk groups. However, how many doses are most appropriate for the protection of high-risk groups is still an issue to be resolved. This study aims to provide the evidence-based clinical guide to help decide the revaccination doses of hepatitis B vaccine that the high-risk young adults without hepatitis B seroprotective antibodies (anti-HBs titer<10 mIU/mL) need to take. Materials and Methods From August 2021 to July 2024, the investigator will invite young adults born in Taiwan over the age of 20 and born after 1987, who have received a full course of hepatitis B vaccine at least three doses at their infant period. Those who are all negative for hepatitis B surface antibodies (anti-HBs) and surface antigens (HBsAg) are enrolled to 4 groups according to the anti-HBs titer concentration (anti-HBs titer between 2.5-10 mIU/mL is a low concentration, anti-HB titer less than 2.5 mIU/mL is an extreme low concentration) with one or two doses of hepatitis B vaccine (Engerix-B) administered, respectively. Each group recruits 60 cases to reach a total of 240 participants. Each participant was followed for 12 months, and the anti-HBs titer concentration was measured in 0, 7-10 days, 28 days, 24- 28 weeks, and 48-52 weeks. The investigator will calculate the anti-HBs titer reaction rate and immune response after receiving hepatitis B vaccine(s) at each stage, and do further univariate and multivariate analysis. Expected Results This prospective cohort study can help understand the difference in the anti-HBs titer response after 1 or 2 revaccination doses by the anti-HBs titer concentration as well as the two different types of hepatitis B vaccination in childhood It is expected to provide an important reference for the administration of hepatitis B vaccine in young adults of high-risk groups.

Official Title
-----------------
The Immune Responses After Hepatitis B Revaccination Doses in a Young Cohort

Conditions
-----------------
Hepatitis B, Vaccination; Infection, Preventable Disease, Vaccine

Intervention / Treatment
-----------------
* Biological: recombinant hepatitis B vaccine


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: The actual age at the time of admission was higher than 20 years old and birth year after 1987 Born in Taiwan and had received a full course of hepatitis B vaccines at least three doses at infant period. Those who have tested negative for hepatitis B surface antibody and surface antigen at baseline Have never been vaccinated against hepatitis B in childhood and adolescence by questionnaire Consent to administer 1-2 doses of hepatitis B vaccine according to the assigned group after sharing decision making process In good health Exclusion Criteria: Those who were previously allergic to hepatitis B vaccine or its components (such as yeast) Those who have been vaccinated against hepatitis B during childhood and adolescence Those who have a positive test for hepatitis B surface antibody or a positive test for hepatitis B surface antigen

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 36 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: prospective cohort study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low titer with two doses of HB Vaccines<br>anti-HBs titer 2.5-10 mIU/mL with two doses of HB Vaccines at Day 0 and Day 28 | Biological: recombinant hepatitis B vaccine<br>* Hepatitis B vaccine (Engerix-B) will be administered to the eligible participants by 4 groups. Each case will be tracked for 12 months, at 0, 7-10 days, 28 days, 24-28 weeks, 48-52 weeks anti-HBs titer concentration and 4 follow-up questionnaires.<br>* Other names: Engerix-B;|
| Active Comparator: Low titer with one dose of HB Vaccine<br>anti-HBs titer 2.5-10 mIU/mL with one dose of HB Vaccine at Day 0 | Biological: recombinant hepatitis B vaccine<br>* Hepatitis B vaccine (Engerix-B) will be administered to the eligible participants by 4 groups. Each case will be tracked for 12 months, at 0, 7-10 days, 28 days, 24-28 weeks, 48-52 weeks anti-HBs titer concentration and 4 follow-up questionnaires.<br>* Other names: Engerix-B;|
| Active Comparator: Extremely low titer with two doses of HB Vaccines<br>anti-HBs titer lower than 2.5 mIU/mL with two doses of HB Vaccines at Day 0 and Day 28 | Biological: recombinant hepatitis B vaccine<br>* Hepatitis B vaccine (Engerix-B) will be administered to the eligible participants by 4 groups. Each case will be tracked for 12 months, at 0, 7-10 days, 28 days, 24-28 weeks, 48-52 weeks anti-HBs titer concentration and 4 follow-up questionnaires.<br>* Other names: Engerix-B;|
| Active Comparator: Extremely low titer with one dose of HB Vaccine<br>anti-HBs titer lower than 2.5 mIU/mL with one dose of HB Vaccine at Day 0 | Biological: recombinant hepatitis B vaccine<br>* Hepatitis B vaccine (Engerix-B) will be administered to the eligible participants by 4 groups. Each case will be tracked for 12 months, at 0, 7-10 days, 28 days, 24-28 weeks, 48-52 weeks anti-HBs titer concentration and 4 follow-up questionnaires.<br>* Other names: Engerix-B;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| anti-HBs titer response rate at 7-10 days | the anti-HBs titer response rate after 1-2 doses of hepatitis B vaccine(s) | 7-10 days | 
| anti-HBs titer response rate at one month | the anti-HBs titer response rate after 1-2 doses of hepatitis B vaccine(s) | 28 days | 
| anti-HBs titer response rate at 6 months | the anti-HBs titer response rate after 1-2 doses of hepatitis B vaccine(s) | 24-28 weeks | 
| anti-HBs titer response rate at 12 months | the anti-HBs titer response rate after 1-2 doses of hepatitis B vaccine(s) | 48-52 weeks | 
| anti-HBs titer immune response change at 12 months | anti-HBs titer immune response change at 12 months after 1-2 doses of hepatitis B vaccine(s) | 48-52 weeks | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
hepatitis B vaccine, revaccination, young adult, booster