The last decade has seen the expansion of basic tools for investigating critical pathways and mechanisms controlling viral diseases in pigs. These include a substantially updated swine genome build with improved annotation of individual genes. These developments have provided the basis for expanded genotyping tools using single nucleotide polymorphisms (SNPs) and application of sophisticated quantitative programs to map genomic locations of relevant genes, thus enabling identification of genetic polymorphisms, or alleles, controlling production phenotypic traits. Simultaneously, scientists have expanded our knowledge of the intricacies of the porcine immune system characterizing mechanisms controlling disease and vaccine responses. As a result substantial progress has been made in identifying critical mechanisms responsible for controlling pig infectious diseases and developing novel therapeutics. 
Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) infections cause large economic losses to swine producers as a respiratory disease in piglets and a reproductive disease in sows (1). This talk will highlight results from the PRRS Host Genomic Consortium which studied nursery pig responses to PRRSV infections and identified the “WUR” allele controlling early immunity to infection, resulting in lower viral load and improved weight gain for pigs with the resistant allele (2). The talk will also explore the complex interactions that occur with congenital PRRSV infections, work in collaboration with Canadian scientists. Despite clear viral replication in the sow not all fetuses become infected. Mechanisms involved in protecting fetuses from viral infection and those involved in fetal demise will be presented. Several quantitative trait loci have been identified that provide the potential to select for improved host anti-viral immunity for both reproductive and respiratory PRRS (3).  
Overall. these viral disease studies have provided alternate targets for design of new vaccines and therapeutics for animal health companies as well as alternate disease resistance alleles for use in genetic selection by pig breeders. This research is part of the US NC229 multi-station research consortium which addresses stakeholder-driven needs to combat swine infectious diseases and identify scientific solutions to improve animal health (4).