Efficacy evaluation on inactivated vaccine made by Nsp2 gene deletion isolate Jiangxi-3 of PRRSV

Inactivated vaccine were made by Jiangxi-3 F9 of PRRSV according to common method,pigs in immunity groups were intramuscularly inoculated with inactivated vaccine.The immunity groups were challenged by 200 LD50 of PRRSV on 21st and 28th after initial immunity and 28th after second immunity.Immunity effect of inactivated vaccine was evaluated by change of body temperature,clinical symptom and regular detection of PRRSV antibody and antigen in sera.Results showed the body temperature in immunity group increased on 21st and 28th after initial immunity.The monitoring of antibody indicates that the specific antibodyagainst PRRSV increases within 21-28 days after the first injection,the antibody on 28th after initial immunity had difference(0.01P0.05) compared with that of 21st after initial immunity.The specific antibody level continued increases after second immunity,the antibody titer on 28th post second immunity had significant difference(0.01P0.05) compared with 28th after initial immunity.PRRSV could bedetected in experiment pigs on 21st and 28th post initial immunity,but PRRSV detection rates,morbidity and fatality were 0 on 28th post second immunity.The results suggested booster on 28th after initial immunity were better than initial immunity.