The 2016 Symposium of Animal Vaccine Development Center

The efficacy of porcine reproductive and respiratory syndrome vaccine III

HY Lee, ZW Chen, WC Huang, YL Zhuo, JP Wang, GF Tseng, JH Lin, TT Peng

Porcine reproductive and respiratory syndrome (PRRS) is one of the important epidemic in the pig herd. The pathogen of PRRS is an enveloped single-strained RNA virus. PRRSV induces reproductive failure of the sow and respiratory tract illness of the piglet. PRRSV is transmitted by droplet contact, i.e. coughing or sneezing on another individual, and attacks the alveolar macrophages. 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 PRRSV subunit vaccines were applied in the sows to induce immune responses (i.e. antibody titers increased), and evaluate the protective effect of maternal antibody in the piglets. Twenty sows were randomly divided into immunized group (n = 11) and control group (n = 9). Five and 3 weeks prior to labor, the sows received PRRSV subunit vaccines injection twice. Blood samples collection, weighing and mortality rates were recorded regularly in the offspring of the sows. The maternal antibodies against PRRSV were measured by commercial ELISA kits. The results showed that survival rate and average weight gain of the immunized sows were significantly higher than control sows. The anti-PRRSV maternal antibodies were observed in the offspring of the immunized sows, and maintained at least 6 weeks. These results showed that PRRSV subunit vaccine application in the sows could transfer the maternal antibody to the piglets, and increased the survival rate and average weight gain in these piglets.