Immunogenicity of formaldehyde and binary ethylenimine inactivated infectious bursal disease virus in broiler chicks

Infectious bursal disease virus (IBDV) was inactivated by two different chemicals—formaldehyde and binary ethylenimine (BEI). Formaldehyde was used at 0.1% and 0.2%, while BEI was used at concentrations of 0.001 and 0.002 mol/L. These four vaccines were tested for their efficiency in generating humoral immune response in different groups of broiler chicks. Both BEI-inactivated vaccines gave relatively higher antibody titers and were almost twice as efficient as formaldehyde-inactivated ones

Resultados preliminares da utilização de cultivos de anéis de traquéia para o estudo de estirpes brasileiras do vírus da bronquite infecciosa das galinhas A preliminary use of tracheal organ cultures for evaluating Brazilian infectious bronchitis virus strains

<abstract language="eng">Tracheal organ cultures (TOC) were prepared and used for evaluating four Brazilian isolates of infectious bronchitis virus (IBV). IBV field isolates and vaccine strains were titrated in TOC and results compared to those from chicken embrionated eggs. Serum neutralization (SN) employing IBV strain-specific serum was performed for evaluating relationships between isolates. Titration results of tests performed in TOC or eggs were in mutual agreement and were considered for validating the adapted TOC methodology as alternative for virological studies in our laboratory. Sera specific to M41 (Massachusetts) or A5968 (Connecticut) did neutralize their respective IBV strains only. Field strains 208 and 29-78 specific sera did neutralize Massachusetts serotype strains M41 and H120, but PM2 serum did only M41. Strain PM4 specific serum did not neutralize any of the reference IBV analyzed, including M41, A5968 and H120 and may indicate that the isolate is serologically different from the Massachusetts serotype, currently adopted for vaccine strains in Brazil

Inactivation of infectious bursal disease virus by binary ethylenimine and formalin

In this experiment conducted to study the inactivation dynamics of infectious bursal disease virus (IBDV) by binary ethylenimine (BEI) in comparison with formalin, IBDV was isolated from the bursa of infected chickens and its confirmation was done by agar gel precipitation test. Viral suspensions were subjected to inactivation with BEI and formalin for pre-set time intervals. BEI was employed at concentrations of 0.001 and 0.002 mol/L while formalin was used at 0.1% and 0.2%. Sampling was done at 6, 12, 24, 36 and 48 h of incubation and samples were tested for their inactivation status in 9-day-old embryonated eggs and 3-week-old broiler chickens. IBDV was completely inactivated by 0.001 and 0.002 mol/L BEI after 36 h of incubation at 37 °C, whereas formalin at 0.1% and 0.2% concentrations inactivated IBDV in 24 h