STABILIZATION OF RESPIRATORY SYNCYTIAL VIRUS (RSV) AGAINST THERMAL INACTIVATION AND FREEZE-THAW CYCLES FOR DEVELOPMENT AND CONTROL OF RSV VACCINES AND IMMUNE GLOBULIN

A high-titered and stable respiratory syncytial virus (RSV) is essenti al for the development of RSV vaccines and quality control of vaccines and RSV immune globulin. We increased the virus titer of RSV seed sto ck, and virus preparations made from this seed stock, 100 times by rem oving defective interfering particles using limiting dilution procedur e. RSV preparations made from the new seed stock had infectivity titer s ranging from 10(7.6) to 10(8.2) TCID50 per ml for five lots made ove r a period of 3 years. Unstabilized RSV lost most of its infectivity a t -86 degrees C within 2-3 weeks, at 37 degrees C within 24 hr, at 56 degrees C within 3 min and after five freeze-thaw cycles. The high tit ered virus was stabilized at -86 degrees C for 3 years, at 37 degrees C for 3 days, at 56 degrees C for 6 min and against five freeze-thaw c ycles. Most effective stabilizers included 25% sucrose, 10% trehalose and 45% fetal bovine serum (FBS) in Medium 199 whereas 3.5% dimethyl s ulfoxide, greater than or equal to 45% FBS in phosphate buffered salin e, 40% glycerol and 10% sorbitol also stabilized RSV to lesser and var iable degrees. A mixture of 0.5% gelatine and 0.3% sodium glutamate st abilized the vir us for a short period whereas 0.1 M MgCl2 and 25% FBS did not stabilize the virus. The stabilized high-titered virus is ver y useful for achieving reproducibility in serologic assays. A broad sp ectrum of stabilizers, such as those evaluated in this study, would be useful in choosing the most suitable formulation for stabilizing a li ve RSV vaccine. Copyright (C) 1996 Elsevier Science Ltd.