Abstract:
The incidence of rabies in Thailand reached its peak in 2018 with 18 human deaths. Preexposure prophylaxis (PrEP) vaccination is thus recommended for high-risk populations. WHO has recently recommended that patients who are exposed to a suspected rabid animal and have already been immunized against rabies should receive a 1-site intradermal (ID) injection of 0.1 mL on days 0 and 3 as postexposure prophylaxis (PEP). In Thailand, village health and livestock volunteers tasked with annual dog vaccination typically receive only a single lifetime PrEP dose and subsequent boosters solely upon confirmed animal bites. However, the adequacy of a single PrEP dose for priming and maintaining immunity in this high-risk group has not been evaluated. Therefore, our study was designed to address two key questions: (1) sufficiency of single-dose PrEP-to determine whether a single ID PrEP dose provides adequate long-term immune protection for high-risk individuals exposed to numerous dogs during their vaccination duties. (2) Booster efficacy for immune maturation-to investigate whether one or two additional ID booster doses effectively stimulate a mature and sustained antibody response in this population. The level and persistence of the rabies antibody were determined by comparing the immunogenicity and booster efficacy among the vaccination groups. Our study demonstrated that rabies antibodies persisted for more than 180 days after cost-effective ID PrEP or the 1st or the 2nd single ID booster dose, and adequate antibody levels were detected in more than 95% of participants by CEE-cELISA and 100% by indirect ELISA. Moreover, the avidity maturation of rabies-specific antibodies occurred after the 1st single ID booster dose. This smaller ID booster regimen was sufficient for producing a sufficient immune response and enhancing the maturation of anti-rabies antibodies. This safe and effective PrEP regimen and a single visit involving a one-dose ID booster are recommended, and at least one one-dose ID booster regimen could be equitably implemented in at-risk people in Thailand and other developing countries. However, an adequate antibody level should be monitored before the booster is administered.
摘要:
泰国狂犬病发病率在2018年达到峰值,有18人死亡。因此,建议对高危人群进行暴露前预防(PrEP)疫苗接种。世卫组织最近建议,暴露于疑似狂犬病动物并已免疫狂犬病的患者应在第0天和第3天接受0.1mL的1位皮内(ID)注射,作为暴露后预防(PEP)。在泰国,负责每年狗疫苗接种的乡村卫生和牲畜志愿者通常只接受一次终生PrEP剂量,并且仅在确认动物咬伤后才接受随后的助推器。然而,在这一高危人群中,单一PrEP剂量用于启动和维持免疫力的充分性尚未得到评估.因此,我们的研究旨在解决两个关键问题:(1)单剂量PrEP的充分性-确定单一IDPrEP剂量是否为在接种疫苗期间暴露于大量狗的高危个体提供足够的长期免疫保护.(2)免疫成熟的加强效力-以研究一个或两个额外的ID加强剂量是否有效地刺激该群体中的成熟和持续的抗体应答。通过比较疫苗接种组之间的免疫原性和加强效力来确定狂犬病抗体的水平和持久性。我们的研究表明,狂犬病抗体在具有成本效益的IDPrEP或第一次或第二次单次ID加强剂量后持续超过180天,通过CEE-cELISA和间接ELISA在超过95%的参与者中检测到足够的抗体水平。此外,狂犬病特异性抗体的亲和力成熟发生在第1次单次ID加强剂量后.这种较小的ID加强方案足以产生足够的免疫应答并增强抗狂犬病抗体的成熟。建议使用这种安全有效的PrEP方案和一次单剂量ID加强检查,在泰国和其他发展中国家的高危人群中,可以公平地实施至少一种单剂量ID加强方案。然而,在加强之前,应监测足够的抗体水平。