PRRS (Porcine reproductive and respiratory syndrome) infected animals develop a stronger and different immune response when infected with a highly virulent virus than with a low virulent virus. Research by CVI showed these differences, when studying the protection and immune response of pigs inoculated with two different PRRS strains.
PRRSV causes significant economic losses to the pork industry worldwide. In many countries pigs are vaccinated for PRRS, but the available vaccines often induce limited protection. Further research into the induced immune responses caused by different virus strains helps to better understand the protecting mechanisms, and can by meaningful for the development of new vaccines.
The research by CVI showed that, although immune responses differed after infection with two different strains, all pigs were fully protected against re-infection with the same virus strain. The outcome can de different when the animals are re-infected with a different strain.
Eefke Weesendorp, Norbert Stockhofe-Zurwieden, Hans J. Nauwynck, Ditta J. Popma-De Graaf, Johanna M.J. Rebel. 2016. Characterization of immune responses following homologous reinfection of pigs with European subtype 1 and 3 porcine reproductive and respiratory syndrome virus strains that differ in virulence. Vet. Microbiol. 182: 64-74.