Shelf Life of Freeze-dried Foot and Mouth Disease Virus Stock Seeds

Foot-and-mouth disease viral strains SAT2/EGY/2012, A Iran 05, and FMDV O PanAsia-2 could remain contagious after freeze-drying with minimum losses in infectivity, with or without additives to virus suspensions. Over 12 months of storage at different temperatures, the infectivity titers of freeze-dried viruses were evaluated on a regular basis. Additive solutions were required to prevent virus degradation throughout freeze-drying and minimize infectivity loss during storage at 4°C and 20°C. Six additives were added as stabilizers forming 6 mixtures: 1-Culture medium without additives; 2- A combination of 5% lactalbumin hydrolysate and 10% w/v sucrose; 3-10% skim milk; 4- A mixture of 10% sucrose and 1% gelatine; 5-A mixture of 4% peptone and 1% gelatine and 6-5% Inositol to prepare virus suspensions for the lyophilization process. Evaluation of obtained lyophilized viruses stored at different temp findings suggested that freeze-dried foot-and-mouth disease virus can be shipped and stored for a brief period which can save storage and transportation expenses using a stabilizer formed of 10% w/v sucrose and 5% Lactalbumin hydrolysate or 10% skimmed milk storage at -20, 0, 4°C.