| abstract |
The present invention provides modified live European PRRS viruses (whether or not recombinant) that have been at all times cultured, maintained, and/or attenuated on non-simian cells, typically porcine cells, wherein such cells express a porcine CD163 receptor, and whereinby vaccines prepared from such viruses are safe and efficacious, and permit the pre-weaning single dose vaccination of swine, typically as early as Day 1 of life. |