《WHO狂犬病专家谘询会第二次报告（英文版）》，已于今年7月3日正式发布（http://blog.sciencenet.cn/blog-347754-713177.html）。

其中第6.6节讲述狂犬病疫苗的保护期能持续多久。以下是此节的译文：

6.6　（狂犬病疫苗的）免疫持续时间

CCEEVs（细胞培养疫苗）建立的免疫记忆估计可在个体中持续终生，尽管中和抗体的滴度会逐渐下降。临床资料确认，即使是在许多年前初次进行过暴露前或暴露后预防接种，接种者对加强免疫都有良好反应，而且与初次或加强免疫的接种途径（肌肉内或皮内）无关，也与在加强接种时是否存在可检测到的狂犬病毒特异性抗体无关。

此外，已发表的数据表明，在初次免疫接种后，并不需要定期进行加强剂量的疫苗接种，除非是因职业原因而有持续或频繁暴露风险的人，对这类人定期加强接种可作为一种补充的预防措施。

不过，所有接种过疫苗的人，如果随后再次暴露于狂犬病（按WHO关于暴露的定义），都应该进行缩短疗程的暴露后预防，具体按第8节（注：第0、3天各接种1针，即共接种2针疫苗即可）。

附原文：

6.6  Duration of immunity

CCEEVs establish immunological memory that presumably persists for the life of the individual even after titres of neutralizing antibodies decline. Clinic data confirm that vaccinated people respond to booster immunization (26–28), even if the initial course of pre- or post-exposure prophylaxis was administer years previously and regardless of the route of priming or booster immunization (intramuscular or intradermal) and the presence or absence of detectable titres of rabies virus-specific antibodies at the time of the booster. In addition, published data indicate that periodic booster doses of vaccine are not required after primary rabies vaccination (29,30), except as an additional precaution for people whose occupation puts them at continual or frequent risk of exposure (see section 8.4). Nevertheless,all vaccinated individuals subsequently exposed to rabies, according to the WHO definition of exposure, should receive an abbreviated course of post exposure prophylaxis, as specified in section 8.