Efficacy of locally prepared inactivated combined vaccine of Salmonella enteritidis, Salmonella typhimurium, Avian influenza (H9N2) and Newcastle disease viruses

This study was conducted to prepare and evaluate the potency of a tetravalent inactivated vaccine for protection of chickens against Salmonella typhimurium, Salmonellaenteritidis, Al-H9N2 and Newcastle disease virus using Montanide ISA-70 VG as an oil adjuvant. The humeral immune response against S. typhimurium and S. enteritidis increased quickly by the 1st wpv, where the mean Log(2) antibody titers were (40 and 20) as measured by micro agglutination test and continue after boostering reached (1280 and 640) in monovalent and tetravalent prepared S. typhimurium, S. enteritidis vaccines on 4th wpb, respectively. S. typhimurium and S. enteritidis monovalent and tetravalent vaccines induced (83.3%, 80% and 86.3%) protection percent in challenged vaccinated birds, respectively. Also the vaccines stimulated the production of specific antibodies against Al-H9N2 and NDV as fast as 1stwpv. Then specific Al-H9N2 mean Log(2) HI antibody titers were (8.6 and 8.8 Log2) at the 4th wpv in monovalent and tetravalent Al-H9N2 vaccines, respectively just before boostering, After that the titer increase gradually reaching (9.4 and 9.8 Log2) at the 4th wpb. NDV mean Log2 HI antibodies titers at the 4th wpb was (11.2 Log2) in tetravalent NDV vaccine than monovalent vaccines was (10.6 Log2). On the other hand, the protection percent for Al-H9N2 and NDV monovalent and tetravalent vaccines reached 100% without any clinical signs observed, while the control+ve unvaccinated group post challenge with Al-H9N2 showed gasping, coughing, nasal and ocular discharge, depression, inappetance, weakness and were relactant to move with 30% mortality. Also, NDV control+ve unvaccinated group showed greenish diarrhia, depression, conjunctivities and nervous manifestations with 90% mortality approving the efficacy of the prepared vaccines. It could be concluded from our study that the tetravalent prepared vaccine can reduce AIV-H9N2, NDV, S.typhimurium and S. enteritidis infections reducing the load on the poultry sector by reducing stress for the worker and the birds.