Khatibzadeh Sarah M, Gold Carvel B, Keggan Alison E, Perkins Gillian A, Glaser Amy L, Dubovi Edward J, Wagner Bettina
Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
Am J Vet Res. 2015 Jan;76(1):92-100. doi: 10.2460/ajvr.76.1.92.
To compare antibody responses of horses naturally infected with West Nile virus (WNV) and those vaccinated against WNV, to identify whether vaccination interferes with the ability to diagnose WNV infection, and to determine the duration of antibody responses after vaccination.
Sera from horses naturally infected with WNV (n = 10) and adult WNV-naïve horses before and after vaccination with a live canarypox virus-vectored vaccine (7) or a killed virus vaccine (8).
An established WNV IgM capture ELISA was used to measure IgM responses. Newly developed capture ELISAs were used to measure responses of 8 other WNV-specific immunoglobulin isotypes. A serum neutralization assay was used to determine anti-WNV antibody titers.
WNV-specific IgM responses were typically detected in the sera of WNV-infected horses but not in sera of horses vaccinated against WNV. Natural infection with and vaccination against WNV induced an immunoglobulin response that was primarily composed of IgG1. West Nile virus-specific IgG1 was detected in the sera of most horses 14 days after vaccination. Serum anti-WNV IgG1 and neutralizing antibody responses induced by the killed-virus vaccines were higher and lasted longer than did those induced by the live canarypox virus-vectored vaccine.
On the basis of these findings, we recommend that horses be vaccinated against WNV annually near the beginning of mosquito season, that both IgM and IgG1 responses against WNV be measured to distinguish between natural infection and vaccination, and that a WNV IgG1 ELISA be used to monitor anti-WNV antibodies titers in vaccinated horses.
比较自然感染西尼罗河病毒（WNV）的马匹和接种WNV疫苗的马匹的抗体反应，确定疫苗接种是否会干扰WNV感染的诊断能力，并确定接种疫苗后抗体反应的持续时间。
自然感染WNV的马匹（n = 10）的血清，以及未感染WNV的成年马匹在接种活金丝雀痘病毒载体疫苗（7匹）或灭活病毒疫苗（8匹）前后的血清。
使用已建立的WNV IgM捕获ELISA法测量IgM反应。使用新开发的捕获ELISA法测量其他8种WNV特异性免疫球蛋白同种型的反应。采用血清中和试验确定抗WNV抗体滴度。
WNV特异性IgM反应通常在WNV感染马匹的血清中检测到，但在接种WNV疫苗的马匹血清中未检测到。WNV自然感染和疫苗接种均诱导了主要由IgG1组成的免疫球蛋白反应。接种疫苗14天后，大多数马匹的血清中检测到西尼罗河病毒特异性IgG1。灭活病毒疫苗诱导的血清抗WNV IgG1和中和抗体反应高于活金丝雀痘病毒载体疫苗诱导的反应，且持续时间更长。
基于这些发现，我们建议在蚊虫季节开始时每年为马匹接种WNV疫苗，检测针对WNV的IgM和IgG1反应以区分自然感染和疫苗接种，并使用WNV IgG1 ELISA监测接种疫苗马匹的抗WNV抗体滴度。
