Comparative analysis of sugar stabilizers on stability of thermo-tolerant vaccine for viral disease control in small ruminants

  • E. Too Department of Biochemistry, Biotechnology and Microbiology, Kenyatta University
  • R. Soi Kenya Agricultural and Livestock Research Organization
  • I. Ogali Kenya Agricultural and Livestock Research Organization
  • E. Masila Kenya Agricultural and Livestock Research Organization
  • A. K. Nyamache Department of Biochemistry, Biotechnology and Microbiology, Kenyatta University

Abstract

Peste des Petits ruminants (PPR) is an acute and contagious viral disease of small ruminants with high morbidity and mortality levels leading to annual losses of up to USD 2.1 billion worldwide. With increased climatic changes coupled with global warming, the current Conventional PPRV vaccines being thermo-labile and required to be kept at 2 °C – 8 °C to maintain viability, this has remained a challenge in the pastoral areas. These vaccines if modified to thermo-tolerant status could make them appropriate for use in areas with hot climatic conditions. This study was therefore aimed at evaluating the stability of two modified thermos-tolerant PPRV vaccines. A total of 108 vials of each lyophilized PPR vaccine with Trehalose + Lactalbumin hydrolysate (LAH) and Sucrose + LAH were exposed to different temperatures and their stability compared. Vaccine vials were incubated in triplicates at 25 °C, 37 °C and 40 °C and observed for viral titres on day 0, 1, 3, 5, 7, 9, 11,13,15,17, 19 and 21. Titre determination were performed by reconstitution of vials in 1 ml of DMEM media and titrated in Vero-SLAM cells and their average log10 titre calculated using Spearman Karber formulae. The infectivity titres rates were analysed using regression tool and T- test in GraphPad Prism 5 software. LAH-Trehalose was found to be more stable compared to LAH-Sucrose with significant high titre values of above log10 2.5TCID100/ ml at different temperature exposures. At 40°C, viral degradation was fast for both LAH-Sucrose and LAH-Trehalose with low insignificant titres values observed on day 7. There was no difference (P>0.05) in the thermal tolerability between LAH -Trehalose and LAH-Sucrose stabilizers when subjected to 25 °C and 40 °C. There was a however a difference (P<0.05) in thermal tolerability for LAH -Trehalose and LAH-Sucrose stabilizer vaccines at temperatures of 37 °C. This study shows that the LAH-Trehalose offered provides a better protection to the vaccine against harsh conditions. This study therefore recommends the use of LAH-Trehalose as the appropriate thermal stabilizer for Peste des Petits ruminants’ vaccine. The adoption and use of this modified PPR vaccine with thermo stabilizer in pastoral areas will  contribute towards animal productivity among the pastoralists

Published
2022-06-02
How to Cite
Too, E., Soi, R., Ogali, I., Masila, E., & Nyamache, A. K. (2022). Comparative analysis of sugar stabilizers on stability of thermo-tolerant vaccine for viral disease control in small ruminants. East African Agricultural and Forestry Journal, 85(1-4), 8. Retrieved from https://www.kalro.org/www.eaafj.or.ke/index.php/path/article/view/523