IMMUNOGENICITY OF ERA G 333 STRAIN IN FOXES
- Slides: 8
IMMUNOGENICITY OF ERA G 333 STRAIN IN FOXES AND RACCOON DOGS D. Bankovskiy(1, 2), G. Safonov(1) and Y. Kurilchuk(1) Pokrov Plant of Biologics, Volginskiy, Russia. (2) All-Russian Research Institute of Veterinary Virology and Microbiology, Pokrov, Russia.
Oral vaccination Ø Two oral vaccines have been used for wild life rabies vaccination in Russia Ø Not enough vaccine quantity have been used for ORV campaigns Ø There was concern about safety and efficacy of vaccine rabies strains Ø Russia still needs a safe and efficient vaccine strain
ERA G 333 Ø Created by reversed genetics Ø Have been received from collaborators at CDC Ø As part of BTEP program Ø Avirulent for 11 species of target and non target animals
The immunogenicity experiment design. Part I: foxes Species # VNA titers, IU/ml Day 60 after Day of death challenge Before Day 30 challenge after challenge Comments fox 1 4. 46 7. 74 5. 87 - fox 2 <0. 04 2. 56 1. 12 - fox 3 2. 56 0. 87 0. 65 - fox 4 <0. 04 2. 56 0. 86 - fox 5 1. 12 1. 14 1. 12 - fox 6 5. 87 1. 12 1. 50 - fox 7 1. 12 2. 51 1. 99 - fox 8 <0. 04 0. 65 0. 87 - fox 9 0. 13 0. 50 0. 29 - fox 10 0. 85 0. 87 1. 14 - fox 11 <0. 04 - - 20 th fox 12 <0. 04 - - 15 th unvaccinated control fox 13 <0. 04 - - 17 th unvaccinated control fox 14 <0. 04 - - 21 st unvaccinated control
The immunogenicity experiment design. Part II: raccoon dogs Species # VNA titers, IU/ml Before Day 30 challenge after challenge Day 60 after challenge Day of death Comments Raccoon dog 1 13. 45 13. 46 10. 44 - Raccoon dog 2 23. 37 21. 43 18. 15 - Raccoon dog 3 2. 56 10. 21 4. 56 - Raccoon dog 4 <0. 04 - - 12 th unvaccinated control Raccoon dog 5 <0. 04 - - 14 th Raccoon dog 6 <0. 04 - - 15 th Raccoon dog 7 <0. 04 0. 50 0. 86 - Raccoon dog 8 <0. 04 - - 21 st Raccoon dog 9 <0. 04 - - 18 th Raccoon dog 10 <0. 04 - - 22 nd unvaccinated control Raccoon dog 11 <0. 04 - - 17 th unvaccinated control
RESULTS 63% of foxes and 33% of raccoon dogs showed seroconversion by day 60 after vaccination. After challenge with virulent rabies virus strain 90% of foxes and 50% of raccoon dogs have survived.
CONCLUSIONS ØThe appropriate immunogenicity of ERA G 333 for foxes and raccoon dogs has been shown in this experiment. ØThis strain is the strong candidate for new oral rabies vaccine. ØThe decision about future use of ERA G 333 strain can be made after the determination of immunity duration and minimal efficient doze of the vaccine virus.
ACKNOWLEDGEMENTS ØPokrov Plant of Biologics ØStaff of the Rabies Program of CDC ØBTEP
