Evaluation of stability of live attenuated camelpox vaccine stabilized with different stabilizers and reconstituted with various diluents

In this study, thermostability of a Vero cell attenuated live camelpox vaccine under conventional lyophilization conditions has been evaluated. Three stabilizers were used separately for freeze-drying the vaccine and the stability of the vaccine, both in freeze-dried and reconstituted forms at different temperatures was assessed. The study revealed that the camelpox vaccine lyophilized with TAA stabilizer found superior with a shelf life of 44 months, 227 days, 22 days and 20 days at 4, 25, 37 and 45 degrees C, respectively followed by LS stabilizer. In terms of half-life, TAA stabilizer proved better followed by LS and BUGS stabilizers at all temperatures except at 25 degrees C in which LS found relatively superior. Among the four diluents viz. 1x PBS (phosphate buffered saline, pH 7.4), 0.85% NaCl, distilled water and 1 M MgSO4, PBS was a better diluent followed by 0.85% NaCl. Both the diluents maintained the infectivity titer more than the minimum effective dose (3 log(10)TCID(50) with a maximum titre of 6.53 log(10)TCID(50) in both the diluents) for 60 h at 37 and 45 degrees C However, 1 M MgSO4 found less suitable for camelpox vaccine dilution. The study indicates that the TAA and 1x PBS are the choice of stabilizer and diluent, respectively for camelpox vaccine. (C) 2014 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.