Stabilizing agent (I) for vaccine compositions comprising one or more live attenuated flavivirus in an aqueous solution without proteins of animal origin and added salts having divalent cations, comprises buffer, sorbitol (2.5-6.5%), saccharose (2.5-13%), trehalose (0-7.5%) and/or di- or tri-saccharide (0-7.5%), urea (0.2-0.5%), a mixture of aminoacids (0.8-2.5%) including arginine, cystine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, tyrosine, valine, alanine, asparagine, aspartic acid, glutamic acid, glycine, proline and serine. Independent claims are included for: (1) an aqueous vaccine composition (II) bulk stabilized with one or more live attenuated flavivirus and (I)； (2) a process of stabilization of one or more live attenuated flavivirus comprising dilution of a purified and concentrated viral harvest having one or more live attenuated flavivirus by adding (I) to obtain definite quantity of (I) in the final concentration for obtaining a composition； (3) a dry vaccine composition obtained by drying of bulk stabilized (II)； (4) a method of preparing a vaccine comprising reconstitution of the dry vaccine composition by an aqueous solution； and (5) kit of an anti-flaviviral vaccine comprising a first container containing the vaccine composition dried by the above method and second container containing an aqueous solution to reconstitute the vaccine. ACTIVITY : None given. MECHANISM OF ACTION : Vaccine. No biological data given.
