Method of producing an immunogenic composition

A method of producing an immunogenic composition comprising a recombinant Porcine circovirus type 2 (PCV2) ORF2 protein, wherein the method comprises the steps of:

• (a)(i) providing a mixture containing
• a first liquid,
• recombinant PCV2 ORF2 protein and/or virus-like particles comprising a plurality of a recombinant PCV2 ORF2 protein, and
• a vector comprising a nucleic acid sequence encoding said recombinant
• PCV2 ORF2 protein;
• (ii) inactivating the vector by adding an inactivating agent to the mixture of step (i);
• (iii) neutralizing the inactivating agent by adding a neutralizing agent to the mixture resulting from step (ii);
• (b) concentrating the recombinant PCV2 ORF2 protein and/or said virus-like particles in the mixture resulting from step (a) (iii) by removing a portion of the first liquid from the mixture, and
• (c) processing the solution resulting from step (b) by continuous diafiltration such that the concentration of the neutralized inactivating agent and the concentration of the neutralizing agent is decreased in the process solution.