Zika virus purification

A process for purifying infectious Zika virus particles, wherein said process comprises the steps of:

• (i) providing a crude harvest (a) comprising infectious Zika virus particles, non-infectious Zika virus particles, and impurities, wherein the impurities are generated from growing Zika virus particles on a cell substrate;
• (ii) contacting said crude harvest (a) with an agent comprising protamine to obtain a Zika virus preparation (b) comprising infectious Zika particles, wherein said agent facilitates separation of infectious Zika particles from non-infectious Zika virus particles;
• and
• (iii) further purifying said Zika virus preparation (b) by one or more size exclusion methods, wherein said one or more size exclusion methods comprise
• (A) sucrose density gradient centrifugation;
• and/or
• (B) a solid-phase matrix packed in a column comprising a ligand-activated core and an inactive shell comprising pores, wherein the pores comprise a molecular weight cut-off that excludes the Zika virus particles from entering the ligand-activated core, and wherein a molecule smaller than the molecular weight cut-off of the pores can enter the ligand-activated core, thereby collecting the Zika virus particles, and/or
• (C) size exclusion chromatography;
• to obtain a final Zika virus preparation (c) comprising infectious Zika virus particles, less than 100 ng/mL residual host cell DNA, less than 1 μg/mL residual host cell protein, and less than 1 μg/mL residual aggregates of Zika virus particles.