Spann Kennedy, Barnum Samantha, Pusterla Nicola
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA.
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA.
J Equine Vet Sci. 2023 Mar;122:104229. doi: 10.1016/j.jevs.2023.104229. Epub 2023 Jan 17.
EHV-1 vaccines are often administered intranasally during emergency situation such as outbreaks of equine herpesvirus myeloencephalopathy. However, there is currently no data available on the efficacy of such protocols, nor the diagnostic challenge when recently vaccinated horses become clinically infected and nasal secretions are collected to support a diagnosis of EHV-1 infection. Therefore, the objective of this study was to determine if two commercially available EHV-1 vaccines, a killed-adjuvanted (Calvenza) and a modified-live (Rhinomune) EHV-1 vaccine, could induce a measurable systemic antibody response postintranasal administration. A second objective was to determine the detection time of EHV-1 in nasal secretions by qPCR following the intranasal administration of the respective EHV-1 vaccines. Thirty healthy adult horses, with no recent EHV-1 vaccine administration, were randomly assigned to one of three groups: Rhinomune group, Calvenza group, and unvaccinated control group. Total Ig and isotype-specific IgG4/7 against EHV-1 measured pre- and 30-days post-vaccination were not different amongst the three study groups. Vaccine-derived EHV-1 was only detected in the two EHV-1 vaccine groups with 9/10 horses in the Rhinomune group and 8/10 horses in the Calvenza group testing qPCR-positive for EHV-1 for 1 to 3 days. There was no significant difference in number of horses testing qPCR-positive for EHV-1 and absolute quantitation of EHV-1 in nasal secretions by qPCR between the two vaccine groups. The intranasal administration of two commercial EHV-1 vaccines did not elicit a systemic immune response. Further, vaccine derived EHV-1 could be detected in the majority of the intranasally vaccinated horses, potentially impacting diagnostic interpretation of EHV-1 during outbreak situations.
在诸如马疱疹病毒性脑脊髓炎爆发等紧急情况下，EHV-1疫苗通常通过鼻内给药。然而，目前尚无关于此类方案疗效的数据，也没有关于近期接种疫苗的马匹出现临床感染并收集鼻分泌物以支持EHV-1感染诊断时的诊断挑战的数据。因此，本研究的目的是确定两种市售的EHV-1疫苗，一种灭活佐剂（Calvenza）和一种减毒活疫苗（Rhinomune）EHV-1疫苗，在鼻内给药后是否能诱导可测量的全身抗体反应。第二个目的是确定在鼻内接种相应的EHV-1疫苗后，通过qPCR检测鼻分泌物中EHV-1的时间。30匹近期未接种EHV-1疫苗的健康成年马被随机分为三组之一：Rhinomune组、Calvenza组和未接种疫苗的对照组。在三个研究组中，接种疫苗前和接种后30天测量的针对EHV-1的总Ig和同种型特异性IgG4/7没有差异。仅在两个EHV-1疫苗组中检测到疫苗衍生的EHV-1，Rhinomune组中有9/10匹马，Calvenza组中有8/10匹马在1至3天内EHV-1的qPCR检测呈阳性。两个疫苗组之间，EHV-1的qPCR检测呈阳性的马匹数量以及通过qPCR对鼻分泌物中EHV-1的绝对定量没有显著差异。两种市售EHV-1疫苗的鼻内给药未引发全身免疫反应。此外，在大多数鼻内接种疫苗的马匹中可检测到疫苗衍生的EHV-1，这可能会影响疫情爆发期间EHV-1的诊断解读。
