Van der Vliet D, Simons de Fanti A, Murri S, Lapidus N, Goujon C, Zeller H, Consigny P H
Institut Pasteur, Centre médical, Centre d'infectiologie Necker-Pasteur, Paris.
Med Trop (Mars). 2010 Apr;70(2):155-7.
Japanese encephalitis vaccine (Jevax) is an inactivated vaccine using the Nakayama viral strain. Until 2007, Jevax was the only Japanese encephalitis vaccine available in France but the duration of seroprotection after vaccination and exact timing of booster injections was unclear for travelers from non-endemic areas. The purpose of this report is to describe the results of a retrospective study in which neutralizing antibody levels were measured in 71 subjects previously vaccinated with Jevax. All subjects underwent testing at the Pasteur Institute Medical Center as part of preparation for humanitarian missions to endemic Japanese encephalitis areas in 2005-2006. A neutralizing antibody level greater than or equal to 20 was considered as protective. Findings showed that 49 of the 71 subjects (69%) still had protective antibody levels at a median of 4 years after the last Jevax immunization. In multivariate analysis, the only factor correlated with long-term seroprotection was the total number of vaccinations received. Based on these findings, it was concluded that long-term seroprotection after Jevax vaccination requires repeated booster injections even in subjects frequently exposed to the virus. No correlation was found between seroprotection and the interval between the booster injections.
日本脑炎疫苗（杰瓦克斯）是一种使用中山病毒株的灭活疫苗。直到2007年，杰瓦克斯是法国唯一可用的日本脑炎疫苗，但对于非流行地区的旅行者来说，接种疫苗后的血清保护持续时间和加强注射的确切时间尚不清楚。本报告的目的是描述一项回顾性研究的结果，该研究测量了71名先前接种过杰瓦克斯疫苗的受试者的中和抗体水平。所有受试者均在巴斯德研究所医疗中心接受检测，作为2005 - 2006年前往日本脑炎流行地区执行人道主义任务准备工作的一部分。中和抗体水平大于或等于20被视为具有保护性。研究结果显示，71名受试者中有49名（69%）在最后一次接种杰瓦克斯疫苗后的中位时间4年时仍具有保护性抗体水平。在多变量分析中，与长期血清保护相关的唯一因素是接种疫苗的总数。基于这些发现，得出的结论是，即使在经常接触该病毒的受试者中，接种杰瓦克斯疫苗后的长期血清保护也需要重复加强注射。未发现血清保护与加强注射间隔之间存在相关性。
