Method for obtaining efficient viral vector-based compositions for vaccination or gene therapy

A method for preparing liquid compositions comprising modified viruses for storage, wherein the modified viruses present in the composition are used to deliver genetic material into cells, the method comprising the steps:

• (a) providing modified viruses selected from modified vaccinia ankara (MVA) viruses, modified adenoviruses, modified Adenovirus-associated viruses (AAV), modified lentiviruses, modified vesicular stomatitis viruses (VSV), or modified herpesviruses for liquid storage;
• (b) providing a solution comprising at least one sugar and at least three but not more than five different amino acids, wherein the different amino acids are selected from at least three different groups from the following:
• amino acids with a polar functional group, amino acids with an aliphatic functional group, amino acids with an aromatic functional group, amino acids with a negatively charged functional group, and amino acids with a positively charged functional group;
• and wherein the solution comprises an amino acid-sugar ratio of no more than twice the amount of sugar as compared to the amount of amino acids;
• and
• (c) mixing the modified viruses of step (a) with the solution of step (b) to form a liquid composition;
• and
• (d) storing the liquid composition of step (c) as a liquid;
• and
• wherein the method does not comprise drying or freezing the liquid composition.