Methods of manufacturing an immunogenic composition comprising a recombinant protein

A method of producing an immunogenic composition comprising a recombinant protein, wherein the method comprises the steps in the following order:

• (i) providing/obtaining a mixture comprising
• a first liquid,
• recombinant protein and/or quaternary structures composed of a plurality of said recombinant protein, and
• a vector comprising a nucleic acid sequence encoding said recombinant protein;
• (ii) adding a second liquid to the mixture of step (i), wherein the second liquid is different from the first liquid;
• (iii) washing the recombinant protein and/or quaternary structures composed of a plurality of said recombinant protein in the mixture by further adding additional second liquid to the mixture resulting from step (ii) and removing a portion of the first and/or second liquid from such combined mixture;
• (iv) inactivating the vector by adding an inactivating agent to the mixture resulting from step (iii);
• and
• (v) neutralizing the inactivating agent by adding a neutralizing agent to the mixture resulting from step (iv).