The 2015 Symposium of Animal Vaccine Development Center

The efficacy of porcine reproductive and respiratory syndrome vaccine II

HY Lee, ZW Chen, WC Huang, CF Lai, JP Wang, JH Lin, TT Peng

Porcine reproductive and respiratory syndrome (PRRS) is a highly epidemic porcine disease which causes huge economic loss. The pathogen of PRRS is a single-strained RNA virus. The disease causes reproductive failure in breeding sow and respiratory tract illness, cyanosis of the ear and fever in piglet. To prevent the economic loss in the pig herd, it is necessary to apply not only feeding management but also vaccination plan. In this study, the effective formulations of PRRSV vaccine were selected by viral challenge tests. Twelve secondary SPF pigs were randomly divided into two immunized groups and one control group. The pigs received twice vaccination at 5 and 7 weeks old and PRRSV challenge at 9 weeks old. Body temperature and clinical symptoms were recorded daily after viral challenge. The commercial ELISA kits were used to examine the anti-PRRSV antibody in the porcine sera. Pathological examinations were carried out in the lung appearance and histologic sections after necropsy. The results indicated that formulation A vaccine induced better immune response and lower fever, and significantly reduced clinical symptoms and pathological scores than control pigs. These results suggested that formulation A vaccine can be a final formulation in PRRSV vaccine development.