| In order to accurately grasp the immunization level of the bivalent inactivated vaccine of H5+H7 highly pathogenic avian influenza virus in high-risk places such as live poultry markets,farms and slaughterhouses in Anhui Province,evaluate the immunization effect of vaccines from different manufacturers,understand the distribution of H7N9 influenza virus,and find out the key links of prevention and control,this study conducted sampling from March to July 2018 in Hefei,Suzhou,Fuyang,Lu’an,Wuhu,Xuancheng and other 7 cities in Anhui Province,each of which selected 20 farms,4 live poultry trading markets(slaughterhouses)and 1 wild poultry habitat(free-range village).Among them,140 farms carried out two rounds of sampling before and 21 days after vaccine immunization,while the rest sites carried out one sampling.The immune effect of H5+H7 bivalent vaccine was evaluated by monitoring the antibody level of poultry H5 and H7 subtype avian influenza before and after vaccination in farms.By monitoring the nucleic acid detection of type A and H5,H7 and H9 subtype avian influenza viruses in all sites,key links of virus contamination were found.The results are as follows:Through serological monitoring,the overall immunization effect of H5+H7 bivalent vaccine is good.Among them,the qualified rate of H5 and H7 subtype immune antibodies in breeding poultry farms,egg poultry farms and chicken farms is over 70%,and that in meat poultry farms and waterfowl farms is below 70%.Vaccines from different manufacturers have different immune effects.The qualified rate of H5 subtype immune antibody has reached the standard,but the qualified rate of H7 subtype immune antibody is uneven.The qualified rate of H7 subtype immune antibody of vaccines from Zhaoqing Dahuanung,Liaoning Yikang and Qingdao Yibang all exceed 70%,while the qualified rate of H7 subtype immune antibody of vaccines from Ganyuanhao,haavikko and Jilin Guanzhong are all lower than 70%.According to the background information of sample immunization,the qualified rate of H5 subtype avian influenza immune antibody has reached the requirements in two rounds of sampling monitoring in the farm.After concentrated immunization in spring,the immunization qualification rate of H7 subtype antibody is close to 70%,which is 69.6%,which is about 13 percentage points higher than that before spring prevention.This shows that the immunization effect of H5+H7 bivalent vaccine is good.The results of two rounds of tests show that the qualified rate of immune antibodies infarms using H5+H7 bivalent vaccines is better than that in farms using vaccines of other strains of bird flu virus,either at the individual level or at the group level.Tests show that the immune effect of more than 2 times is better than that of 1 time.Through etiological monitoring,influenza A virus nucleic acids were detected in farmers’ markets,wholesale markets,farms and free-range farming villages,among which H5 subtype avian influenza virus nucleic acids were detected in farmers’markets,H9 subtype avian influenza virus nucleic acids were detected in wholesale markets,farmers’ markets and free-range farming villages,and H7 subtype avian influenza virus nucleic acids were not detected in all links.The results show that breeding links,trading links and free-range farming households are risk links of avian influenza virus pollution,especially in farmers’ markets and live poultry trading markets,and the A type avian influenza virus pollution is serious.Conclusion:The immune effect of H5+H7 bivalent vaccine is good.Vaccines from different manufacturers have different immune effects.The immune effect of more than 2 times is better than that of 1 time.Breeding,trading and casual farmers are the risk links of bird flu virus pollution. |
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