A method of producing a PCV-2 antigen composition comprising the steps of: i) obtaining a first liquid containing the PCV-2 antigen comprising virus-like particles of the ORF-2 protein； and ii) separating at least a portion of the first liquid of the PCV-2 antigen comprising virus-like particles from the ORF-2 protein by a filtration step using a filter, wherein the filter includes a semipermeable membrane having a average pore size that is smaller than the PCV-2 antigen to avoid the passage of at least 90% of the PCV-2 antigen through the pores of the semipermeable membrane and retain the PCV-2 antigen within the filter, wherein the portion of the first liquid is separated from the PCV-2 antigen by exchanging the portion of the first liquid against a second liquid, where the second liquid is different from the first liquid, and wherein the exchange of the portion of the first liquid with second liquid comprises the steps of: a) adding liquid comprising adding the second liquid to the first liquid containing the PCV-2 antigen； and b) concentration of the PCV-2 antigen from 3X to 50X compared to the volume of the first liquid by separating a portion of the first and second liquids； and iii) mixing the PCV-2 antigen remaining after step ii) with an additional component selected from the group consisting of pharmaceutically acceptable carriers, adjuvants, diluents, excipients, and combinations thereof.Un método para producir una composición antigénica de PCV-2 que comprende las etapas de: i) obtener un primer líquido que contiene el antígeno de PCV-2 que comprende partículas similares a virus de la proteína ORF-2； y ii) separar al menos una porción del primer líquido del antígeno de PCV-2 que comprende partículas similares a virus de la proteína ORF-2 mediante una etapa de filtración que utiliza un filtro, en donde el filtro incluye una membrana semipermeable que tiene un tamaño de poro promedio que es más pequeño que el antígeno de PCV-2 para evitar así el paso de al
