The present invention in particular relates to a method of producing an immunogenic composition exhibiting reduced virucidal activity, as well as to the immunogenic composition and uses thereof, wherein the method in particular comprises the steps of: (a) providing a mixture with a first liquid and a recombinant protein, (b) concentrating the recombinant protein in the mixture by removing a portion of the first liquid from the mixture, and (c) processing the solution resulting from step (b) by continuous diafiltration.本發明特別關於製造展現降低之殺病毒活性之免疫原組合物的方法，以及該免疫原組合物，及其用途，其中該方法特別包含以下步驟：(a) 提供具有第一液體及重組蛋白之混合物，(b) 藉由自該混合物去除一部分該第一液體而濃縮該混合物中之重組蛋白，及(c) 藉由連續滲濾處理步驟(b)產生之溶液。
