Background:
PPR is a highly contagious and an important transboundary disease of small ruminants that severely impact Indian as well as global rural economy. The disease is found in Africa, Middle East, India and Central Asia. WOAH and FAO have targeted the global eradication of the PPR by 2030. Currently Nigeria 75/1 and Sungri/96 live attenuated vaccines are available for PPR control. Although these vaccines are extremely safe and efficacious, both suffer from the same disadvantage of thermal lability, which is considered a bottle-neck for successful global eradication of PPR:
Technology Details:
We have imparted thermotolerance to PPRV/Sungri/96 vaccine virus through a specific thermo-adaptation process and developed Thermoadapted Sungri (Ta Sungri) with the same production scalability and better thermotolerance than normal Sungri virus and vaccines at all tested temperature. Most notably, at the temperature for storage and transportation of PPR vaccines, Ta Sungri vaccine could retain shelf life for 6.5 months more than the parent non-adapted Sungri vaccine of the same initial titre. Standard PPR vaccine formulation was made using Ta Sungri and the safety and efficacy of Ta Sungri vaccine was evaluated in both sheep and goats. Ta Sungri retained the same safety and efficacy profiles of the normal Sungri/96 vaccine in both the target species. Therefore, Ta Sungri can be used as a thermotolerant alternate to the existing PPR vaccine strains that are presently being used in the PPR control/eradication program:
To further strengthen our claim, we have also confirmed the acquired thermo-tolerance at genetic level, through comparative genome sequencing studies of Ta Sungri and normal Sungri viruses. As the thermo-tolerance is intrinsic to the vaccine virus, there are additional scopes to further enhance the thermo-tolerance of finished products by combining Ta Sungri with established extrinsic process modification methodologies at production houses.