The present invention relates to formulation comprising (i) at least one virus-based material, (ii) at least one polymer selected in the group of polyvinylpyrrolidone and derivatives thereof, (iii) at least one sugar, (iv) at least two different amino acids, (v) at least two pharmaceutical acceptable salts, wherein at least one of said salts is a phosphate salt and, optionally (vi) a pharmaceutical acceptable buffer. Such a formulation is particularly suitable for freeze-drying. The present invention also relates to the corresponding dry product, as well as its preparation process. The present invention also relates to a reconstituted material comprising said dry product, which can be administered to a patient in need thereof. Such formulation and reconstituted material are useful as vaccines, preferably for the treatment and/or the prevention of cancers, infectious diseases and/or autoimmune disorders.
