Cross-protection elicited by primary and booster vaccinations against Japanese encephalitis: A two-year follow-up study
Cross-protection elicited by primary and booster vaccinations against Japanese encephalitis: A two-year follow-up study
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DOI：
10.1016/j.vaccine.2013.10.055
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发表时间：
2013-12-17
期刊：
影响因子：
5.5
通讯作者：
Kantele, Anu
中科院分区：
文献类型：
--
作者：
Erra, Elina O.;Askling, Helena Hervius;Kantele, Anu
背景资料：Vero细胞衍生灭活疫苗（JE-VC，IXIARO）已取代传统的小鼠脑衍生制剂（JE-MB）用于旅行者预防乙脑的疫苗接种。我们最近发现，单剂量JE-VC有效地增强了JE-MB致敏疫苗接种者的免疫力，并且JE-VC增强了针对非疫苗基因型（包括新出现的基因型I）的交叉保护性免疫力。虽然这些研究只提供了短期的数据，目前的调查评估寿命的seroprotection在相同的volunteers.Methods：这项研究包括48名旅客谁收到（1）乙脑-VC的主要系列，（2）乙脑-MB的主要系列，其次是一个单一的乙脑-VC加强剂量，或（3）乙脑-MB的主要系列和一个单一的乙脑-MB加强剂量。在末次接种疫苗后2年采集血清样本，并采用空斑减少中和试验对代表基因型I-IV的7种日本脑炎病毒株进行评价。PRNT 50滴度>= 10被认为是保护性的。结果：在用JE-VC进行初级系列试验两年后，87-93%的疫苗接种者被证明对代表基因型II-IV的试验菌株具有交叉保护作用，73%对基因型I的试验菌株具有交叉保护作用。结论：乙脑疫苗接种后，对基因型Ⅰ ~ Ⅳ的血清保护率最高，为89- 100%。第一个助推器不应拖延超过两年。在JE-MB致敏受试者中，单次JE-VC加强免疫在几乎所有接种者中提供了针对基因型I-IV菌株的交叉保护性免疫，这表明第二次加强免疫的间隔时间为两年甚至更长。这些数据进一步支持使用单次JE-VC剂量来增强JE-MB免疫力。(C)2013作者由爱思唯尔有限公司出版。保留所有权利。
Background: The inactivated Vero cell-derived vaccine (JE-VC, IXIARO) has replaced the traditional mouse brain-derived preparations (JE-MB) in travelers' vaccinations against Japanese encephalitis. We showed recently that a single JE-VC dose efficiently boosts immunity in JE-MB-primed vaccinees, and that JE-VC elicits cross-protective immunity against non-vaccine genotypes, including the emerging genotype I. While these studies only provided short-term data, the present investigation evaluates the longevity of seroprotection in the same volunteers.Methods: The study comprised 48 travelers who had received (1) JE-VC primary series, (2) JE-MB primary series followed by a single JE-VC booster dose, or (3) JE-MB primary series and a single JE-MB booster dose. Serum samples were collected two years after the last vaccine dose, and evaluated with the plaque-reduction neutralization test against seven Japanese encephalitis virus strains representing genotypes I-IV. PRNT50 titers >= 10 were considered protective.Results: Two years after the primary series with JE-VC, 87-93% of the vaccinees proved to be cross-protected against test strains representing genotypes II-IV and 73% against those of genotype I. After a single homologous or heterologous booster dose to JE-MB-primed subjects, the two-year seroprotection rates against genotype I-IV strains were 89-100%.Conclusions: After JE-VC primary series, seroprotection appeared to wane first against genotype I. The first booster should not be delayed beyond two years. In JE-MB-primed subjects, a single JE-VC booster provided cross-protective immunity against genotype I-IV strains in almost all vaccinees, suggesting an interval of two years or even longer for the second booster. These data further support the use of a single JE-VC dose for boosting JE-MB immunity. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.