Marcelino Isabel, Lefrançois Thierry, Martinez Dominique, Giraud-Girard Ken, Aprelon Rosalie, Mandonnet Nathalie, Gaucheron Jérôme, Bertrand François, Vachiéry Nathalie
CIRAD, UMR CMAEE, F-97170 Petit-Bourg, Guadeloupe, France.
CIRAD, UMR CMAEE, F-34398 Montpellier, France.
Vaccine. 2015 Jan 29;33(5):678-85. doi: 10.1016/j.vaccine.2014.11.059. Epub 2014 Dec 13.
The use of cheap and thermoresistant vaccines in poor tropical countries for the control of animal diseases is a key issue. Our work aimed at designing and validating a process for the large-scale production of a ready-to-use inactivated vaccine for ruminants. Our model was heartwater caused by the obligate intracellular bacterium Ehrlichia ruminantium (ER). The conventional inactivated vaccine against heartwater (based on whole bacteria inactivated with sodium azide) is prepared immediately before injection, using a syringe-extrusion method with Montanide ISA50. This is a fastidious time-consuming process and it limits the number of vaccine doses available. To overcome these issues, we tested three different techniques (syringe, vortex and homogenizer) and three Montanide ISA adjuvants (50, 70 and 70M). High-speed homogenizer was the optimal method to emulsify ER antigens with both ISA70 and 70M adjuvants. The emulsions displayed a good homogeneity (particle size below 1 μm and low phase separation), conductivity below 10 μS/cm and low antigen degradation at 4 °C for up to 1 year. The efficacy of the different formulations was then evaluated during vaccination trials on goats. The inactivated ER antigens emulsified with ISA70 and ISA70M in a homogenizer resulted in 80% and 100% survival rates, respectively. A cold-chain rupture assay using ISA70M+ER was performed to mimic possible field conditions exposing the vaccine at 37 °C for 4 days before delivery. Surprisingly, the animal survival rate was still high (80%). We also observed that the MAP-1B antibody response was very similar between animals vaccinated with ISA70+ER and ISA70M+ER emulsions, suggesting a more homogenous antigen distribution and presentation in these emulsions. Our work demonstrated that the combination of ISA70 or ISA70M and homogenizer is optimal for the production of an effective ready-to-use inactivated vaccine against heartwater, which could easily be produced on an industrial scale.
在贫穷的热带国家使用廉价且耐热的疫苗来控制动物疾病是一个关键问题。我们的工作旨在设计并验证一种用于大规模生产反刍动物即用型灭活疫苗的工艺。我们的模型是由专性细胞内细菌反刍兽埃立克体（ER）引起的牛心水病。传统的抗牛心水病灭活疫苗（基于用叠氮化钠灭活的全菌）在注射前立即制备，采用与Montanide ISA50的注射器挤压法。这是一个繁琐且耗时的过程，并且限制了可用疫苗剂量的数量。为克服这些问题，我们测试了三种不同技术（注射器、涡旋仪和匀浆器）以及三种Montanide ISA佐剂（50、70和70M）。高速匀浆器是用ISA70和70M佐剂乳化ER抗原的最佳方法。乳液显示出良好的均匀性（粒径低于1μm且相分离低）、电导率低于10μS/cm以及在4℃下长达1年的低抗原降解。然后在山羊的疫苗接种试验中评估不同制剂的效力。用匀浆器中用ISA70和ISA70M乳化的灭活ER抗原分别导致80%和100%的存活率。使用ISA70M+ER进行了冷链破裂试验，以模拟在交付前将疫苗在37℃下暴露4天的可能现场条件。令人惊讶的是，动物存活率仍然很高（80%）。我们还观察到，用ISA70+ER和ISA70M+ER乳液接种的动物之间MAP-1B抗体反应非常相似，这表明这些乳液中抗原分布和呈递更均匀。我们的工作表明，ISA70或ISA70M与匀浆器的组合对于生产有效的抗牛心水病即用型灭活疫苗是最佳的，这种疫苗可以很容易地在工业规模上生产。
