Abstract: Biologically-active material can be preserved by a method of desiccation, without lyophilisation, in a matrix of glassy trehalose. The method involves forming a coacervate of the biologically-active material and chitosan and then dehydrating mixture of coacervate and trehalose solution. In a cycle time much shorter than a typical freeze drying process biologically-active material, such as viruses, proteins and nucleic acids, can be preserved to provide a material that can be rehydrated. The invention is especially useful for the production of vaccines from preserved material.

Abstract: A biologically-active material comprising a live virus or mycoplasma is preserved by a method of desiccation, without lyophilisation, in a matrix of glassy trehalose having a residual moisture content of not greater than 2%. The method comprises two vacuum drying stages. In a cycle time much shorter than a typical freeze drying process a virus or mycoplasma can be preserved to provide a material that can be rehydrated to give a vaccine having potency.