Immunomodulatory effect of plasmids co-expressing cytokines in classical swine fever virus subunit gp55/E2-DNA vaccination Daniel Wienhold, Elisenda Armengol, Annette Marquardt, Christian Marquardt, Heiner Voigt, Mathias Büttner, Armin Saalmüller and Eberhard Pfaff Vet. Res., 36 4 (2005) 571-587 DOI: 10.1051/vetres:2005019