Global Biologics Research, Zoetis - Vet Med R & D, 333 Portage Road, Kalamazoo, MI 49007, USA.
Global Therapeutic Research, Zoetis - Vet Med R & D, 333 Portage Road, Kalamazoo, MI 49007, USA.
Virus Res. 2014 Aug 8;188:60-7. doi: 10.1016/j.virusres.2014.03.007. Epub 2014 Mar 29.
Highly virulent, systemic strains of Feline calicivirus (vs FCV) have been described in recent years. These vs FCV isolates cause severe edema, cutaneous ulcers, lameness and other upper respiratory and oral clinical signs typically associated with FCV infection in cats. Vs FCV isolates can cause high mortality even in cats vaccinated with currently available commercial vaccines. This study reports identification and characterization of an avirulent FCV strain (FCV 21). This strain offers a broader serum cross-neutralization profile in comparison with the commonly used vaccine strain (FCV F9), as tested with two separate viral panels of FCV isolates. The first viral panel consists of 45 FCV strains isolated around 1993. The second viral panel consists of 26 FCV strains with most isolated around 2003. The potential of using this strain as a vaccine, in a 3-way (FCV+FHV+FPV) or 4-way (FCV+FHV+FPV+FCp) format, was tested by using a highly virulent vs FCV strain (FCV-33585) as a challenge virus. The mortality induced by this vs FCV in unvaccinated control cats was 78% (7 out of 9 cats). The mortality decreased to 44% (4 out of 9 cats) in cats vaccinated with a 4-way vaccine containing FCV F9. However, when this novel FCV vaccine strain (FCV 21) was used, either in combination with FCV F9 or by itself, the mortality decreased to 0% (0 out of 10 cats). The 3-way vaccine (FCV+FHV+FPV) that contained both FCV 21 and FCV F9 also had mortality of 0% (0 out of 10 cats). The clinical scores, as calculated taking into consideration the frequency and severity of various clinical signs, correlated with mortality data. The results suggested this FCV vaccine has the potential to be broadly protective against newly emergent FCV isolates, including complete protection against challenge with a highly virulent vs FCV 33585.
近年来，已描述了具有高度毒力的系统性猫杯状病毒（FCV）菌株。这些与 FCV 相比的分离株会引起严重的水肿、皮肤溃疡、跛行和其他上呼吸道和口腔临床症状，这些症状通常与猫的 FCV 感染有关。即使在接种了现有市售疫苗的猫中，与 FCV 相比的分离株也会导致高死亡率。本研究报告了一种无毒力 FCV 株（FCV 21）的鉴定和特征。与常用疫苗株（FCV F9）相比，该株在针对两个单独的 FCV 分离株病毒组的血清交叉中和试验中具有更广泛的血清交叉中和谱。第一个病毒组由 1993 年左右分离的 45 株 FCV 组成。第二个病毒组由 26 株 FCV 组成，其中大多数是在 2003 年左右分离的。使用高度毒力的与 FCV 相比的分离株（FCV-33585）作为挑战病毒，测试了该株作为疫苗在 3 种（FCV+FHV+FPV）或 4 种（FCV+FHV+FPV+FCp）格式中的应用潜力。未接种疫苗的对照猫中，这种与 FCV 相比的分离株引起的死亡率为 78%（9 只猫中有 7 只）。在接种包含 FCV F9 的 4 种疫苗的猫中，死亡率降至 44%（9 只猫中有 4 只）。然而，当使用这种新型 FCV 疫苗株（FCV 21）时，无论是单独使用还是与 FCV F9 联合使用，死亡率均降至 0%（10 只猫中无死亡）。包含 FCV 21 和 FCV F9 的 3 种疫苗（FCV+FHV+FPV）的死亡率也为 0%（10 只猫中无死亡）。根据各种临床症状的频率和严重程度计算得出的临床评分与死亡率数据相关。结果表明，这种 FCV 疫苗有可能广泛预防新出现的 FCV 分离株，包括对高度毒力的与 FCV 33585 的完全保护。
