Study on the Immune Effects of Recombinant Avian Influenza VirusBivalent Inactivated Vaccines(H5N1 Re-8+H7N9 H7-Re1 Strain)in Pheasants
In order to evaluate theimmune effects of recombinant avian influenza virus(A/V) bivalentinactivated vaccines(H5N1 Re-8+H7N9 H7-Re1 strain)in pheasants,30-day-old pheasants wereselected for first vaccination,followed by boostervaccination after 21 days according to immune procedures,and their blood samples were collected regularly before and aftervaccination respectively to test the titers of HI antibodies against H5 and H7subtype AIV. The results showed that,before vaccination,the titers of HI antibodies against H5 and H7 subtypes in the serumof pheasants were 0;and the average titers of H5 and H7subtypes could reach to 7.0log2 and 7.07log2 respectively after 14 days,then increased to the peak after 49 days,whichwere 8.04log2 and 9.20log2 respectively;the immunevalidity for H5 subtype AIV could remain for 105 days or above,and that for H7 subtype could be up to 189 days,which indicated the immune effects and security of bivalentinactivated vaccines were good. However,the titers ofH5 and H7 antibodies decreased gradually after 49 days of vaccination,then decreased significantly after 133 days,andthe qualified rates at herd level was less than 70%. Therefore,it was suggested that,after the firstimmunization at the age of 30 days,the reinforcedvaccination should be carried out at the ages of 51 days and 5 monthsrespectively. In conclusion,the research would providesome references for selecting vaccines(for rare andprecious birds)and developing relevant procedures.