Purification processes for isolating purified vesicular stomatitis virus from cell culture

A process for purifying vesicular stomatitis virus (VSV) from cell culture fluid of a mammalian cell culture infected with VSV, the process comprising:

• (a) clarifying the cell culture fluid by low-speed centrifugation or by a 1.0 μm to 4.5 μm depth filtration module and recovering the VSV in the supernatant, wherein the VSV is secreted from the infected mammalian cells;
• (b) filtering the supernatant of step (a) through a 0.2 to 0.45 μm filter and recovering the VSV in the filtered solution;
• (c) loading the VSV filtered solution of step (b) onto an anion exchange membrane adsorber equilibrated with a first pH buffered salt solution, wherein the salt in the first pH buffered salt solution has an ionic strength of at least about 100 mM to about 400 mM;
• eluting the VSV from the anion exchange membrane adsorber with a second pH buffered salt solution, wherein the VSV is eluted from the membrane adsorber by adding the second pH buffered salt solution in a single step, wherein the single step elution concentration of the salt is between 500 mM to 750 mM;
• and recovering the eluted VSV fractions;
• (d) purifying the VSV recovered in step (c) by tangential flow filtration (TFF) using a membrane having a molecular weight cutoff between 300 kDa and 1,000 kDa and recovering the VSV in the retentate, and
• (e) filtering the VSV retentate from step (d) through a 0.2 to 0.22 μm filter and recovering the VSV in the filtered solution, wherein the VSV recovered is at least 90% to about 99% free of cell culture protein and nucleic acid contaminants and further wherein 70-95% of the VSV is recovered.