Elanco Animal Health, Solheimsgaten 18, N-5058, Bergen, Norway.
Experimental Pathology Laboratories Inc., 45600 Terminal Drive, Sterling, VA, 20166, USA.
Fish Shellfish Immunol. 2021 Jan;108:116-126. doi: 10.1016/j.fsi.2020.12.002. Epub 2020 Dec 4.
Pancreas disease (PD) caused by salmonid alphavirus subtype 3 (SAV3) is a serious disease with large economic impact on farmed Norwegian Atlantic salmon production despite years of use of oil-adjuvanted vaccines against PD (OAVs). In this study, two commercially available PD vaccines, a DNA vaccine (DNAV) and an OAV, were compared in an experimental setting. At approximately 1040° days (dd) at 12 °C post immunization, the fish were challenged with SAV3 by cohabitation 9 days after transfer to sea water. Sampling was done prior to challenge and at 19, 54, and 83 days post-challenge (dpc). When compared to the OAV and control (Saline) groups, the DNAV group had significantly higher SAV3 neutralizing antibody titers after the immunization period, significantly lower SAV3 viremia levels at 19 dpc, significantly reduced transmission of SAV3 to naïve fish in the latter part of the viremic phase, significantly higher weight gain post-challenge, and significantly reduced prevalence and/or severity of SAV-induced morphologic changes in target organs. The DNAV group had also significantly higher post-challenge survival compared to the Saline group, but not to the OAV group. The data suggest that use of DNAV may reduce the economic impact of PD by protecting against destruction of the pancreas tissue and subsequent growth impairment which is the most common and costly clinical outcome of this disease.
鲑鱼甲肝病毒 3 型（SAV3）引起的胰腺疾病（PD）是一种严重的疾病，尽管多年来一直使用针对 PD 的油佐剂疫苗（OAV），但对养殖挪威大西洋鲑的生产仍有很大的经济影响。在本研究中，在实验环境中比较了两种市售的 PD 疫苗，一种是 DNA 疫苗（DNAV），另一种是 OAV。在大约 1040°天（dd）在 12°C 免疫后，在转移到海水后 9 天通过共感染对鱼进行 SAV3 挑战。在挑战前和挑战后 19、54 和 83 天（dpc）进行采样。与 OAV 和对照（盐水）组相比，DNAV 组在免疫期后具有显著更高的 SAV3 中和抗体滴度，在 19 dpc 时具有显著更低的 SAV3 病毒血症水平，在病毒血症后期显著降低了 SAV3 向幼稚鱼的传播，显著提高了攻毒后的增重，显著降低了 SAV 诱导的靶器官形态变化的流行率和/或严重程度。DNAV 组的攻毒后存活率也显著高于盐水组，但与 OAV 组无显著差异。数据表明，使用 DNAV 可能通过保护胰腺组织免受破坏和随后的生长障碍来减轻 PD 的经济影响，这是该疾病最常见和最昂贵的临床结果。
