Comparative Study of Japanese Encephalitis, Live Attenuated Vaccine Potency by CCID50 and PFU Method

Japanese Encephalitis, live attenuated vaccine is a cell culture derived (Primary Hamster Kidney), live attenuated vaccine based on the SA 14-14-2 strain manufactured by China and is imported to India. The potency of a live vaccine is typically expressed in terms of the number of infectious unit of viruses contained in human doses using a specified tissue culture substrate. Both BHK-21 cell line as well as vero cell line shows good susceptibility for JE Virus. WHO recommends the use of BHK-21 cell line or any other cell line acceptable to the National Control Authority. In the present study the potency of the JE vaccine was performed by CCID50 & PFU method using Vero cell line.