| Newcastle Disease(ND) and Avian Influenza(AI) are the two main diseases which have been influencing the development of poultry industry for a long time. Newcastle Disease Virus belongs to Paramyxoviridae family, paramyxovirus genus.The nucleic acid type of this virus is single-stranded, negative-sense, nonsegmented RNA. Avian Influenza Virus belongs to Influenza virus A genus of Orthomyxovoridae .Its genome is composed of 8 negative-sense, single-stranded RNA segments.Some scholars from home and abroad have done some researches about the relationship between antigen concentration and antibody titers in oil-emulsion inactivated Newcastle Disease and Avian Influenza vaccines by different aqueous-to-oil ratios and using different immunizing doses, but in this experiment, allantoic-fluid(AF) is diluted by different times first, and then emulsified by the same aqueous-to-oil ratios(ND 1:3,AI H5subtype 1:2,H9subtype 1:3) with certain rotate speed and time, three to four week old commercial chickens without special maternal antibodies were vaccinated subcutaneously at the later one third of the neck with 0.3ml of each vaccine.The influence of vaccine with different antigen concentration on immune efficacy and the correlation between antigen concentration and antibody were analysed by detecting blood sera at different time points after immunization.The results indicate that there is a correlation between antigen concentration and antibody titers in both ND and AI vaccines, but the correlation coefficients between antigen concentration and antibody titers of different vaccines are different. As far as ND vaccine is concerned, it can stimulate the chicken's immune system to produce detectable antibody only when the antigen concentration is higher than 3.13%.When the vaccine's antigen concentration is up to 12.50%,there will be no distinct difference between it and the vaccine with antigen concentration of 25.00%,it indicates that when antigen concentration is up to 12.50%,the antibody titer arrives at the climax; In the vaccine of AI H5 subtype, also it will stimulate the chicken's immune system to produce detectable antibody only when antigen concentration is higher than 4.17%,the difference is that when antigen concentration is up to13.33%,the antibody titer will arrive at the climax, and there isn't any significant difference between it and the antibody titer of the vaccine with antigen concentration of 33.33%;However,to the vaccine of AI H9 subtype,it will stimulate chicken's immune system to produce antibody quickly only when antigen concentration is higher than 0.78%,the needing of antigen concentration for antibody arriving at the climax is also 10.00%,which is as high as that of the AI H5 subtype vaccine .There also exist a certain correlation between antigen concentration and the variation coefficient about antibody titers in all three vaccines. Along with the increase of the antigen concentration, the variation coefficient about antibody titers will decrease gradually.It means that the antibody titers are tending to orderliness gradually. |
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