The effect of killed and/or MLV vaccination on exposure to late term pregnant gilts

PRRS virus is the most significant swine disease in the industry today, probably the most significant swine disease in history for North America. The AASV has made a challenge to eradicate the virus within the next two decades. In order to do this, we must be able to stop farms from becoming re-infected. There is significant economic loss to the sow farm. Unfortunately the losses downstream are even more substantial. Any intervention which can reduce or eliminate the amount of virus shedding from a farm in the outgoing pigs improves our chances of keeping regions PRRS negative. One intervention to reduce the amount of virus exiting a sow farm with the pigs, or to help stabilize sow farms and increase the likelihood of sending out negative pigs, is to vaccinate. While not perfect, in the field, vaccination has been shown to reduce viral load. Two new and novel approaches have arisen in the industry recently, which hope to further stabilize a sow herd and improve the chance of producing negative pigs. There also is the anticipation that if re-infected, the clinical disease and financial losses at the sow herd itself can be lessened. While both of these killed vaccines are being used in the field, controlled scientific data as to their real merit is lacking.