Efficacy of Hepatitis B Vaccine Boosters Among Neonatally Vaccinated Children in Chongqing

Study Overview
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Brief Summary
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Worldwide, hepatitis B virus (HBV) infection is a major cause of acute hepatitis, and chronic infection with HBV often leads to chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. So far, the most effective way to prevent HBV infection in susceptible population is to inject hepatitis B vaccine. However, long-term protection against hepatitis B virus (HBV) after vaccination remains widely debated. This study aims to carry out a comprehensive study to evaluate the efficacy of hepatitis B vaccine booster from the aspect of humoral and cellular immunity in neonatally vaccinated children in Chongqing.

Detailed Description
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Hepatitis B virus (HBV) infection is a major public health problem around the world. More than 2 billion people have been infected with HBV. Although the World Health Organization (WHO) has incorporated hepatitis B vaccination into routine immunization programs for infants and adolescents since 1986 to reduce the incidence of chronic liver diseases, liver cirrhosis and hepatocellular carcinoma associated with hepatitis B virus, there are still more than 400 million chronic carriers. Although it is currently recognized that the most effective way to prevent HBV infection in susceptible population is to inject hepatitis B vaccine, the protective effect of the neonatally vaccinated children weakened as time goes on, which involves the question of the need of boosters. However, there are still some problems concerning hepatitis B vaccine boosters for healthy children. In China, there has not been a standardized directory to guide hepatitis B vaccine booster. Scholars have great controversy on the necessity, age, dosage and other aspects of hepatitis B vaccine booster. Researchers conducted an investigation on the Anti-HBs level of 93,326 Chinese children aged 1 - 16 who completed basic immunization. The results showed that the proportion of HBsAb positive in children aged 1 - 8 years old decreased dramatically, with 8 - year - old children having the lowest proportion of protective antibody. Therefore, this study is intended to explore the protective effect of hepatitis B vaccine on the body and the effect of multiple vaccines. This study will recruit some healthy children with anti-HBs at a low level (titer <10mIU/mL and [10,100) mIU/mL) in Chongqing and conduct selective re-vaccination according to the results of the first detection of hepatitis B surface markers in healthy children. According to the changes of immune status after booster, the efficacy of hepatitis B vaccine boosters was comprehensively evaluated.

Official Title
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Efficacy of Hepatitis B Vaccine Boosters Among Neonatally Vaccinated Children in Chongqing

Conditions
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Hepatitis B Vaccine Adverse Reaction

Intervention / Treatment
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* Biological: hepatitis B vaccine(HepB)


Participation Criteria
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Eligibility Criteria
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Born after Jan. 1st, 2005 in Chongqing, China; Completion of the full primary immunization of HepB after birth; No HBV booster vaccine history.

Ages Eligible for Study
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Minimum Age: 1 Year
Maximum Age: 15 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Hepatitis B vaccine booster<br>Children with anti-HBs at a level of<10mIU/mL or [10,100) mIU/mL before booster. | Biological: hepatitis B vaccine(HepB)<br>* Children with anti-HBs at a low level (<10mIU/mL and [10,100) mIU/mL) were received a dose of hepatitis B vaccine booster after informed consent.<br>|
| Observation<br>Children with anti-HBs at a level of >100mIU/mL or [10,100) mIU/mL before booster. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| HBsAb positive rate | The proportion of HBsAb in children with and without hepatitis B vaccine boosters | 3-year | 
| HBsAg-specific T cell response | The proportion of HBsAg-specific IFN-γ-producing T cells in children with and without hepatitis B vaccine boosters | 3-year | 
| HBsAb protective efficacy | Evaluate the changes in the protective efficacy of HBsAb after hepatitis B vaccine booster | 3-year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hepatitis B Vaccine, booster, Immune response