Assessment of antibody and T cell responses during simultaneous co-infection with swine influenza A and porcine reproductive and respiratory syndrome virus

Porcine respiratory disease is multifactorial and most commonly involves pathogen co-infections. Major contributors include swine influenza A and porcine reproductive and respiratory syndrome viruses. Experimental co-infection studies with these two viruses have shown that clinical outcomes can be exacerbated but how innate and adaptive immune responses contribute to pathogenesis and pathogen control have not been thoroughly evaluated. We investigated immune responses following experimental simultaneous co-infection of pigs with swIAV H3N2 and PRRSV-2. Our results indicate that clinical disease was not significantly exacerbated. In coinfected animals lung H3N2 viral load was reduced and H3N2 specific IgG serum titers and H3N2 specific IFNg CD8b responses enhanced.