Serological Monitoring of an H5 Inactivated Vaccine in Layer Farms, Iran, 2018

Background and aims: avian influenza (ai) is an acute infectious disease of poultry,waterfowl, wild birds, and animals, zoonotically transmitted to humans. some incidents ofhpai are reported in iran: h5n1 and h5n8. iranian veterinary organization decides onvaccination (h5) of layer and breeder flocks in high-risk provinces following the outbreak iniran. this study aimed to evaluate the serum response of the vaccine in the layer flocks ofhigh-risk provinces.materials and methods: ten laying farms (size: 30000-50000) were selected from qazvin(no: 2) and isfahan (no: 8) provinces that received the h5 vaccine (four farms: 1 time; 6farms: 2 times of vaccine shots). twenty-five blood samples were taken from each flock. thehi test was carried out in a u-bottomed microtiter plate and 4 ha units of homologousantigen.results: the mean titers of antibodies in the poultry farms that received the vaccine oncewere 1.87, while those that received the immunization twice were 4.90 (significantdifference; p<0.05). also, if we consider protection baseline 4, 4 out of 6 flocks (~67%)could make it above it. injection of the vaccine twice also improved cv.conclusion: in combination with other control measures such as good biosecurity andmonitoring programs, vaccination is considered a suitable and powerful tool to support aieradication or control programs in endemically infected countries if the iranian veterinaryorganization (ivo) did regular post-vaccination surveillance and evaluated the flocks forsilent infections.