Thieulent Côme J, Sutton Gabrielle, Toquet Marie-Pierre, Fremaux Samuel, Hue Erika, Fortier Christine, Pléau Alexis, Deslis Alain, Abrioux Stéphane, Guitton Edouard, Pronost Stéphane, Paillot Romain
LABÉO, 14280 Saint-Contest, France.
BIOTARGEN EA 7450, Normandie University, UNICAEN, 14280 Saint-Contest, France.
Pathogens. 2022 May 4;11(5):539. doi: 10.3390/pathogens11050539.
Equid alphaherpesvirus-1 (EHV-1) is one of the main pathogens in horses, responsible for respiratory diseases, ocular diseases, abortions, neonatal foal death and neurological complications such as equine herpesvirus myeloencephalopathy (EHM). Current vaccines reduce the excretion and dissemination of the virus and, therefore, the extent of an epizooty. While their efficacy against EHV-1-induced abortion in pregnant mares and the decreased occurrence of an abortion storm in the field have been reported, their potential efficacy against the neurological form of disease remains undocumented. No antiviral treatment against EHV-1 is marketed and recommended to date. This study aimed to measure the protection induced by valganciclovir (VGCV), the prodrug of ganciclovir, in Welsh mountain ponies experimentally infected with an EHV-1 ORF30-C strain. Four ponies were administered VGCV immediately prior to experimental EHV-1 infection, while another four ponies received a placebo. The treatment consisted in 6.5 mg/kg body weight of valganciclovir administered orally three times the first day and twice daily for 13 days. Clinical signs of disease, virus shedding and viraemia were measured for up to 3 weeks. The severity of the cumulative clinical score was significantly reduced in the treated group when compared with the control group. Shedding of infectious EHV-1 was significantly reduced in the treated group when compared with the control group between Day + 1 (D + 1) and D + 12. Viraemia was significantly reduced in the treated group when compared with the control group. Seroconversion was measured in all the ponies included in the study, irrespective of the treatment received. Oral administration of valganciclovir induced no noticeable side effect but reduced clinical signs of disease, infectious virus shedding and viraemia in ponies experimentally infected with the EHV-1 C variant.
马疱疹病毒1型（EHV-1）是马的主要病原体之一，可引发呼吸道疾病、眼部疾病、流产、新生驹死亡以及诸如马疱疹病毒性脑脊髓炎（EHM）等神经并发症。目前的疫苗可减少病毒的排泄和传播，从而降低 epizooty 的程度。虽然已有报道称其对怀孕母马中EHV-1诱导的流产有效，且能减少田间流产风暴的发生，但它们对神经型疾病的潜在疗效仍未得到证实。迄今为止，尚无针对EHV-1的抗病毒治疗药物上市并被推荐使用。本研究旨在测量更昔洛韦的前体药物缬更昔洛韦（VGCV）对实验性感染EHV-1 ORF30-C株的威尔士山地小马的保护作用。四匹小马在实验性感染EHV-1之前立即给予VGCV，而另外四匹小马接受安慰剂。治疗方法为第一天口服6.5mg/kg体重的缬更昔洛韦，每日三次，之后13天每日两次。对疾病的临床症状、病毒脱落和病毒血症进行了长达3周的测量。与对照组相比，治疗组的累积临床评分严重程度显著降低。与对照组相比，治疗组在第1天（D + 1）至第12天之间传染性EHV-1的脱落显著减少。与对照组相比，治疗组的病毒血症显著降低。对研究中纳入的所有小马进行了血清转化测量，无论其接受何种治疗。口服缬更昔洛韦未引起明显副作用，但可减轻实验性感染EHV-1 C变体的小马的疾病临床症状、传染性病毒脱落和病毒血症。
