Cholera, an acute watery diarrhoeal disease caused by Vibrio cholerae serogroup O1 and O139 across the continents. Replacing the existing WHO licensed killed multiple-dose oral cholera vaccines that demand ‘cold chain supply’ at 2–8 °C with a live, single-dose and cold chain-free vaccine would relieve the significant bottlenecks and cost determinants in cholera vaccination campaigns. In this direction, a prototype cold chain-free live attenuated cholera vaccine formulation (LACV) was developed against the toxigenic wild-type (WT) V. cholerae O139 serogroup. LACV was found stable and retained its viability (5 × 106 CFU/mL), purity and potency at room temperature (25 °C ± 2 °C, and 60% ± 5% relative humidity) for 140 days in contrast to all the existing WHO licensed cold-chain supply (2–8 °C) dependent killed oral cholera vaccines. The LACV was evaluated for its colonization potential, reactogenicity, immunogenicity and protective efficacy in animal models after its storage at room temperature for 140 days. In suckling mice colonization assay, the LACV recorded the highest recovery of (7.2 × 107 CFU/mL) compared to those of unformulated VCUSM14P (5.6 × 107 CFU/mL) and the WT O139 strain (3.5 × 107 CFU/mL). The LACV showed no reactogenicity even at an inoculation dose of 104–106 CFU/mL in a rabbit ileal loop model. The rabbits vaccinated with the LACV or unformulated VCUSM14P survived a challenge with WT O139 and showed no signs of diarrhoea or death in the reversible intestinal tie adult rabbit diarrhoea (RITARD) model. Vaccinated rabbits recorded a 275-fold increase in anti-CT IgG and a 15-fold increase in anti-CT IgA antibodies compared to those of rabbits vaccinated with unformulated VCUSM14P. Vibriocidal antibodies were increased by 31-fold with the LACV and 14-fold with unformulated VCUSM14P. The vaccine formulation mimics a natural infection, is non-reactogenic and highly immunogenic in vivo and protects animals from lethal wild-type V. cholerae O139 challenge. The single dose LACV formulation was found to be stable at room temperature (25 ± 2 °C) for 140 days and it would result in significant cost savings during mass cholera vaccination campaigns.

中文翻译：

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活的口服霍乱疫苗制剂在冷链外保存140天的免疫原性和保护功效。

霍乱是由霍乱弧菌O1和O139血清群在整个大陆引起的一种急性水样腹泻病。将现有的世卫组织许可的要求灭活的多剂量口服霍乱疫苗替换为需要在2–8°C下“冷链供应”的实时，单剂量和无冷链疫苗，将缓解霍乱疫苗接种活动中的重大瓶颈和成本决定因素。在这个方向上，针对毒原性野生型（WT）霍乱弧菌O139血清群开发了无冷链减毒活霍乱减毒活疫苗的原型。发现LACV稳定并在室温下（25°C±2°C，相对湿度60％±5％）保持其活力（5×106 CFU / mL），纯度和效能140天世卫组织许可的依赖冷链供应（2-8°C）的灭活口服霍乱疫苗。在室温下保存140天后，在动物模型中评估了LACV的定殖潜力，反应原性，免疫原性和保护功效。与未配制的VCUSM14P（5.6×107 CFU / mL）和WT O139菌株（3.5×107 CFU / mL）相比，在乳鼠定植试验中，LACV的回收率最高（7.2×107 CFU / mL）。在兔回肠loop模型中，即使接种剂量为104–106 CFU / mL，LACV也没有显示出反应原性。接种了LACV或未配制的VCUSM14P的兔子在WT O139的攻击下存活下来，并且在可逆肠成年兔子腹泻（RITARD）模型中没有腹泻或死亡的迹象。与未接种VCUSM14P的兔子相比，接种疫苗的兔子的抗CT IgG抗体增加了275倍，抗CT IgA抗体增加了15倍。LACV使杀弧抗体增加了31倍，未配制的VCUSM14P使杀弧抗体增加了14倍。该疫苗制剂模仿自然感染，在体内无反应性和高度免疫原性，可保护动物免受致命的野生型霍乱弧菌O139攻击。发现单剂量LACV制剂在室温（25±2°C）下可稳定140天，在大规模霍乱疫苗接种活动中可节省大量成本。具有体内无反应性和高度免疫原性，可保护动物免受野生型霍乱弧菌O139致死性攻击。发现单剂量LACV制剂在室温（25±2°C）下可稳定140天，在大规模霍乱疫苗接种活动中可节省大量成本。具有体内无反应性和高度免疫原性，可保护动物免受野生型霍乱弧菌O139致死性攻击。发现单剂量LACV制剂在室温（25±2°C）下可稳定140天，在大规模霍乱疫苗接种活动中可节省大量成本。