Hepatitis B virus immunity in Indigenous and "at risk" children who received hepatitis B vaccination in infancy

在婴儿期接受乙型肝炎疫苗接种的土著儿童和“高危”儿童的乙型肝炎病毒免疫力

• 批准号: nhmrc : 396700
• 负责人: A/Pr Nicholas Wood
• 金额: $ 14.25万
• 依托单位: The Children's Hospital at Westmead
• 依托单位国家: 澳大利亚
• 项目类别: NHMRC Project Grants
• 财政年份: 2006
• 资助国家: 澳大利亚
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://researchdata.edu.au/hepatitis-b-virus-vaccination-infancy/76863
• 关键词: Hepatitis; virus; immunity; Indigenous; risk

Hepatitis B virus (HBV) is transmitted by blood exposure or sexual contact and infection can result in chronic liver disease and liver cancer. Since 2000 Hepatitis B virus immunisation has been recommended for all infants in Australia with the first dose given at birth. However, prior to routine universal immunisation, a selective immunisation strategy was used in Australia from 1986. This targeted infants considered at high risk of HBV infection because of high prevalence in their population of origin, (including Aboriginal- Torres Strait Islanders) and infants whose mother was a HBV carrier. These children, among the first to be vaccinated, are now adolescents. There have been no long-term follow-up studies in Australia, and limited studies elsewhere, to assess the extent of breakthrough infection and persistence of immunity to Hepatitis B after vaccine at birth. As onset of sexual activity is associated with an increased exposure to hepatitis B infection, booster doses may be needed, especially in high-risk individuals. This study includes 2 high risk groups - young indigenous adults in the Northern Territory and young adults born to HBV carrier mothers in central Sydney. It will measure the number of children who have been infected with HBV or are chronic carriers, compared to pre immunisation data, and also the persisting level of immunity in children who were vaccinated against HBV as an infant. Children whose blood test indicates that they have low immunity will be given a booster dose of HBV vaccine and their immune response measured. A rise in hepatitis B antibody following booster vaccination indicates that you have immunological memory and is currently considered to show protection from natural hepatitis B infection. If clinically significant HBV infections are found to be rare and immunologic memory can be demonstrated, this would provide good evidence to support the argument that booster vaccine doses are not required in the Australian context.

B型肝炎病毒（HBV）通过血液接触或性接触传播，感染可导致慢性肝病和肝癌。自2000年以来，建议澳大利亚所有婴儿在出生时接种第一剂B型肝炎病毒疫苗。然而，在常规普遍免疫之前，澳大利亚从1986年开始使用选择性免疫策略。这一方案针对的是被认为有高风险感染乙肝病毒的婴儿，因为他们的原籍人口（包括土著-托雷斯海峡岛民）和母亲是乙肝病毒携带者的婴儿的发病率很高。这些儿童属于第一批接种疫苗的儿童，现在是青少年。在澳大利亚没有长期的随访研究，在其他地方的研究有限，以评估突破性感染的程度和出生时接种疫苗后对B型肝炎免疫力的持续性。由于性活动的开始与接触B型肝炎感染的增加有关，可能需要加强剂量，特别是在高危人群中。这项研究包括2个高危人群-北领地的年轻土著成年人和悉尼市中心HBV携带者母亲所生的年轻成年人。它将测量与免疫前数据相比感染HBV或慢性携带者的儿童数量，以及在婴儿时期接种HBV疫苗的儿童的持续免疫水平。血液检查表明免疫力低下的儿童将接受乙肝疫苗的加强剂量，并测量其免疫反应。加强接种后B型肝炎抗体升高表明您具有免疫记忆，目前被认为对自然感染B型肝炎具有保护作用。如果发现临床上显著的HBV感染是罕见的，并且可以证明免疫记忆，这将提供很好的证据来支持在澳大利亚背景下不需要加强疫苗剂量的论点。