SOME STUDIES ON THE IMMUNITY OF RODENTS VACCINATED WITH COMBINED ROTA VIRUS (RV), CORONA VIRUS (CV) AND K99 E. COLI VACCINE AND ITS ROLE IN EPIZOOTIOLOGY OF THE DISEASE

SHAFAY, SAMY M.; AHMED, IMAN K.; WASSEL, MOHAMED S.; ZEIDAN, SAYED M.

doi:10.21608/ejar.2000.321709

SOME STUDIES ON THE IMMUNITY OF RODENTS VACCINATED WITH COMBINED ROTA VIRUS (RV), CORONA VIRUS (CV) AND K99 E. COLI VACCINE AND ITS ROLE IN EPIZOOTIOLOGY OF THE DISEASE

Document Type : Original Article

Authors

¹ Central Laboratory for Evaluation of Veterinary Biologics, Agricultural Research Centre, Ministry of Agriculture, Giza, Egypt

² Veterinary Serum and Vaccine Research Institute, Agricultural Research Centre, Ministry of Agriculture, Giza, Egypt

10.21608/ejar.2000.321709

Abstract

In this study, a combined vaccine of rota virus, corona virus and enterotoxigenic K99 E.. toll ( ETEC) was evaluated against safety, sterility and potency in pregnant mice, as well as, in their infants. The antibody level was measured in dams and their infants, using serum neutralization test for rota, corona viruses, microagglutination test and mouse protection test for K99 E..coli .A challenge test was conducted in vaccinated mice, as well as, in their infants using virulent strain of rota, corona viruses and K99 E.. coli strain and in control group. Trials for reisolation of these challengin strain were done and confirmed by using indirect fluorescent antibogdy technique ( IFA) for rota and corona viruses and specific media and biochemical test for K99 E..coli strain. The vaccine was safe and potent for dams mice and their infants as the level of antibody titres, by using microagglutination test, was 430 geometric mean "GM" for dams mice and 355 GM for in fant mice, where the protective level was 80 GM. The mouse protection test in dams mice reached 100% and in infant mice was 80% . The serum neutralization titre (SNT) was 2.1 log ₁₀ SN titre for dams and 1.2 log_i0 titre for infants for rota virus and 2.1log_i0 SN titre dams, 1.5 log ₁₀ SN titre for corona virus, where the protective level was 0.6 log₁₀ SN titre for rota and corona visuses. The vaccine protected infant mice against challenge with virulent strains and study emphathized the transmission of passive immunity from vaccinated dams mice to their infant mice it was clear that, mice play an important role in transmission of infection through their faeces to contaminate animal rations, as well as, human food .