Biologically safe, non-transmissible pseudorabies virus vector vaccine protects pigs against both Aujeszky's disease and classical swine fever.

Abstract

Envelope glycoprotein D (gD) of pseudorabies virus (PRV) is essential for penetration but is not required for cell-to-cell spread. When animals are inoculated with a phenotypically complemented PRV gD mutant, the virus is able to spread locally by means of direct cell-to-cell transmission, but progeny virions released by infected cells are non-infectious because they lack gD. Therefore, the virus cannot be transmitted from inoculated animals to other animals. This property makes a PRV gD mutant an attractive candidate as a safe vaccine vector. To examine whether a self-restricted, non-transmissible PRV mutant can be used as a biologically safe vaccine vector, a gD/gE-negative PRV recombinant virus which expresses envelope glycoprotein E2 of classical swine fever virus was constructed. Vaccination of pigs showed that the recombinant virus was able to protect pigs against both Aujeszky's disease and classical swine fever.

Immunomodulatory effect of plasmids co-expressing cytokines in classical swine fever virus subunit gp55/E2-DNA vaccination

“…Marker vaccines based on recombinant glycoprotein E2 allow discrimination between vaccinated and infected animals. Several groups working on CSFV vaccines have shown that especially the E2-protein is able to induce a specific and protective immune response against CSFV after vaccination with an E2-expressing recombinant virus [17,22,32], by immunization with baculovirus expressed E2 protein [5,44,45]. These experiments have demonstrated that glycoprotein E2 is the most immunogenic and protective protein of CSFV inducing e.g.…”

Control and eradication of Classic Swine Fever in wild boar

“…The E2 subunit vaccine was demonstrated to protect specific pathogen free (SPF) piglets against the clinical course of the disease two weeks after double vaccination or 6 weeks after a single vaccination (Hulst et al, 1993;Konig et al, 1995;Van Rijn et al, 1996;Peeters et al, 1997). More recently, it was demonstrated that, with 32 micrograms E2 in a water-oilwater adjuvant, a protective immunity was conferred as early as 21 days after a single vaccination .…”

“…C-strain-based vaccines are also used for oral immunization of wild boar with vaccine carrying baits (Kaden et al, 2001a(Kaden et al, , 2001b(Kaden et al, , 2001c. In Germany, C-strain baits were used in several federal states like Mecklenburg-Western Pommerania, Rhineland Palatinate and North-Rhine-Westphalia (Kaden et al,2002(Kaden et al, , 2003(Kaden et al, , 2004a(Kaden et al, , 2005 During the development of marker vaccines it became clear that the E2-glycoprotein in a purified form was capable of inducing a protective immunity (Rümenapf et al, 1991;Van Zijl et al, 1991;Hulst et al, 1993;Konig et al, 1995;Van Rijn et al, 1996;Peeters et al, 1997). This finding was the basis for the development of an E2 subunit vaccine that contains as antigen only the E2 glycoprotein of CSFV.…”

“…-Detection of ERNS or NS3-antibodies specific for CSVF or pestiviruses, e.g. using blocking ELISAs Konig et al, 1995;van Zijl et al, 1991;Hooft van Iddekinge et al, 1996;Mulder et al, 1994;Peeters et al, 1997;Hammond et al, 2000Hammond et al, , 2001Hammond et al, , 2003Hahn et al, 2001;…”

Generation and Efficacy Evaluation of a Recombinant Pseudorabies Virus Variant Expressing the E2 Protein of Classical Swine Fever Virus in Pigs

“…Among the various types of vaccines available, MLVs are often preferred over inactivated or subunit ones, because MLVs are able to induce long-lasting humoral and cell-mediated immunity (22).…”