Efficacy of var 206 vaccination against infectious bronchitis virus in broiler chickens in Babylon, Iraq

Abstract

The production of chicken is still severely hampered by the infectious bronchitis virus (IBV), which causes respiratory illnesses, decreased productivity, and large losses. Despite routine immunization, outbreaks continue to occur often in Iraq. Under field conditions in Babylon Province, this study examined the effectiveness of immunization programs in broiler chickens, with a particular emphasis on the Var206 vaccine. Five groups of 260 Ross 308 chicks each were formed. One group was used as an unvaccinated control, and the other four groups got various combinations of the Newcastle disease virus (NDV) and IBV vaccinations. ELISA was used to measure antibody titers at various ages. The findings demonstrated that the strongest and most reliable immune response against IBV was generated by two doses of Var206.Programs such as Clone 30 and LaSota had the highest levels of NDV immunity. These findings emphasize the practical importance of Var206 as a homologous vaccine and the need to adapt vaccination strategies to local field strains in Iraq.