Sorbitol-gelatin and glutamic acid-lactose solutions for stabilization of reference preparations of measles virus

The work reported here sought to assess the protection afforded by two stabilizing solutions (sorbitol-gelatin and glutamic acid-lactose) in preserving the potency of freeze-dried Schwarz strain measles virus during storage with a view to the production of reference preparations and working lots of virus suspensions. Stabilized virus suspensions and control suspensions were stored at -70 degrees C or were freeze-dried and stored at -20 degrees C, and their potency was determined over a storage period of 21 months. It was found that the sorbitol-gelatin imparted more satisfactory stability (r = +0.18) to the freeze-dried virus suspensions than did the glutamic acid-lactose. The results also indicate that sorbitol-gelatin, used under the conditions of this study, is an effective stabilizer in the preparation of freeze-dried suspensions of Schwarz strain measles virus employed as reference preparation working lots.