Thermostabilizing Potential of L-Glutamic Acid Monosodium Salt and other Factors Improving The Quality of Peste des Petits Ruminants Virus Vaccine.

Ayad Samia, Mouaz Mohamed, Kamel Nahed, Abdel-Wahab Afaf and Daoud Ahmed.

Rinderpest Research and Vaccine Production Department, Veterinary Serum and Vaccine Research Institute, Abbasia, Cairo, Egypt.

Two peste des petits ruminants virus (PPRV) vaccine batches (A and B) were manufactured synchronously with an attenuated PPRV on Vero cells. Aspects of vaccine batch A were: a) incorporation of 1% monosodium glutamate (MSG) in the PPRV inoculum for 5 roller Vero cell culture bottles, b) incorporation of 1% of the same salt in the vaccine stabilizer (wt/volume) and c) incorporation of 1% of the same salt in the vaccine diluent (normal physiological saline solution). These aspects were lacking in PPRV vaccine batch B. Comparative studies revealed that, the incorporation of MSG resulted in a) detectable enhancement of PPRV yields in roller culture bottles of Vero cells, b) yield antibody stability in vaccinated susceptible sheep and c) significant improvement of thermostability potential of the lyophilized vaccine at -20^oC. The actual mechanism of action of MSG in these respects has to be assessed.