Classical swine fever (CSF) is an important viral disease of pigs and controlled by vaccination. Unorganised backyard and wild pigs are difficult to vaccinate by needle vaccination. Here we formulated liquid vaccines using an Indian CSF cell culture vaccine virus and four stabilisers and evaluated their stability at 4 °C, 25 °C and 37 °C up to 24 h for use as oral vaccine. The stabilisers were Lactalbumin hydrolysate-Trehalose, Lactalbumin hydrolysate-Trehalose-Gelatin, Lactalbumin hydrolysate-Lactose-Sucrose and Lactalbumin hydrolysate-Sucrose. The liquid vaccines, with or without stabilisers, were stable at 4 °C up to 24 h, whereas, a drop of one log₁₀ titre was observed at 25 °C during the same period. At 37 °C, the virus titre diminished by only one log₁₀ with the Lactalbumin hydrolysate-Trehalose (LT) stabiliser up to 24 h compared to two log₁₀ losses in virus titre with other stabilisers and virus control. We therefore conclude that for developing a CSF oral vaccine, the vaccine virus in liquid form can be used directly during the winter, whereas for developing the oral vaccine for summer, the LT stabiliser would provide maximum stability to the virus to withstand the warm temperature while maintaining adequate therapeutic titre for inducing a protective immune response.

猪瘟（CSF）是一种重要的猪病毒性疾病，通过疫苗接种得到控制。无组织的后院和野猪很难通过针头接种疫苗。在这里，我们使用印度脑脊液细胞培养疫苗病毒和四种稳定剂配制液体疫苗，并评估它们在 4°C、25°C 和 37°C 下长达 24 小时的稳定性，用作口服疫苗。稳定剂是乳清蛋白水解物-海藻糖、乳清蛋白水解物-海藻糖-明胶、乳清蛋白水解物-乳糖-蔗糖和乳清蛋白水解物-蔗糖。有或没有稳定剂的液体疫苗在 4 °C 下可保持稳定长达 24 小时，而在同一时期，在 25 °C 下观察到滴度为1 log ₁₀。在 37 °C 时，病毒滴度仅下降 1 个 log ₁₀使用乳清蛋白水解物-海藻糖 (LT) 稳定剂最多 24 小时，而其他稳定剂和病毒对照的病毒滴度损失为两个 log ₁₀。因此，我们得出结论，对于开发 CSF 口服疫苗，液体形式的疫苗病毒可以在冬季直接使用，而对于开发夏季口服疫苗，LT 稳定剂将为病毒提供最大的稳定性以抵御温暖的温度，同时维持足够的治疗滴度以诱导保护性免疫反应。