Vaccination methods to control PCV2 infection with different PCV2 subtypes are disclosed. Specifically, a PCV2 subtype b (PCV2b) ORF2 proteins or immunogenic compositions comprising a PCV2b ORF2 protein are used in a method for the treatment or prevention of an infection with PCV2 of the same PCV2b and/or different subtype; the reduction, prevention or treatment of clinical signs caused by an infection with PCV2 of the same PCV2b or a different subtype; and/or the prevention or treatment of a disease caused by an infection with PCV2 of the same PCV2b and/or a different subtype. The present invention in particular relates to PCV2 subtype b (PCV2b) ORF2 proteins characterized in that they contain at least one mutation in the BC loop that such that the expressed protein is preferably expressed in a higher amount compared to a PCV2 ORF2 protein that does not contain such mutation.

The present invention relates to the use of an immunogenic composition that comprises a porcine circovirus type 2 (PCV2) antigen for treatment of several clinical manifestations (diseases). Preferably, the clinical manifestations are associated with a PCV2 infection. Preferably, they include lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes. Moreover, the clinical symptoms include lymphadenopathy in combination with one or a multiple of the following symptoms in pigs: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc. Furthermore the clinical symptoms include Pia like lesions, normally known to be associated with Lawsonia intracellularis infections.

Vaccination methods to control PCV2 infection with different PCV2 subtypes are disclosed. Specifically, a PCV2 subtype b (PCV2b) ORF2 proteins or immunogenic compositions comprising a PCV2b ORF2 protein are used in a method for the treatment or prevention of an infection with PCV2 of the same PCV2b and/or different subtype; the reduction, prevention or treatment of clinical signs caused by an infection with PCV2 of the same PCV2b or a different subtype; and/or the prevention or treatment of a disease caused by an infection with PCV2 of the same PCV2b and/or a different subtype. The present invention in particular relates to PCV2 subtype b (PCV2b) ORF2 proteins characterized in that they contain at least one mutation in the BC loop that such that the expressed protein is preferably expressed in a higher amount compared to a PCV2 ORF2 protein that does not contain such mutation.

The present invention relates to the expression of polypeptides using Yarrowia lipolytica, in particular the secretion of expressed polypeptides into either the extracellular space or the surface of the Y. lipolytica host cell wall. The invention also extends to the use of the polypeptides so expressed in biotechnological applications. The present invention provides an expression construct for the expression of polypeptides using at least a single Yarrowia lipolytica yeast cell, the expression construct having at least one expression cassette, the expression cassette including an acid extracellular protease secretion signal sequence and flanking zeta sequence recombination sites.

Vaccination methods to control PCV2 infection with different PCV2 subtypes are disclosed. Specifically, a PCV2 subtype b (PCV2b) ORF2 proteins or immunogenic compositions comprising a PCV2b ORF2 protein are used in a method for the treatment or prevention of an infection with PCV2 of the same PCV2b and/or different subtype; the reduction, prevention or treatment of clinical signs caused by an infection with PCV2 of the same PCV2b or a different subtype; and/or the prevention or treatment of a disease caused by an infection with PCV2 of the same PCV2b and/or a different subtype. The present invention in particular relates to PCV2 subtype b (PCV2b) ORF2 proteins characterized in that they contain at least one mutation in the BC loop that such that the expressed protein is preferably expressed in a higher amount compared to a PCV2 ORF2 protein that does not contain such mutation.

The present invention relates to the use of an immunogenic composition that comprises a porcine circovirus type 3 (PCV3) antigen for treatment of several clinical manifestations (diseases). Preferably, the clinical manifestations are associated with a PCV3 infection.

The invention provides a method of preparing a vaccine composition. The method includes infecting gene-edited porcine endogenous retrovirus (PERV) negative swine cells with a microorganism which expresses at least one protein antigen capable of inducing protective immunity in an animal against an infectious agent; culturing the infected cells in culture medium to propagate the microorganism; and harvesting the propagated microorganism from the culture medium to obtain a fraction comprising a PERV free antigen for use in immunizing an animal against the infectious agent.