Abstract
The long-term survival of lapinized-avianized (LA) rinderpest virus preserved by freeze-drying was examined in order to aim the storage of rinderpest live virus vaccine. The viral materials of LA rinderpest virus multiplied in Vero cell cultures were freeze-dried in vials after mixing with an equal volume of protective agent consisting of 10% succharose (4% or 8% glucose in some cases), 1% glutamate and 1% gelatin. Then the vials were filled up with pure nitrogen gas and stored in refrigerator at 4℃ during over six years. The freeze-dried virus specimens exhibited a survival of 58% on the average by the process of freeze-drying. An average of 65% of survival rate was obtained through the preservation, although some lots showed 16% of minimum survival rate and the survival rate of the viral specimens which stored at 4℃ for 6 years was about 23%. A slightly increasing tendency was seen on the moisture rate of the specimens during the preservation, however, it was difficult to find a certain relationship between moisture and survival rates. The survival rate of specimens filled up with nitrogen gas was significantly high than that of the sealed one in vacuo after the preservation for over seven years. From the results mentioned above, it was suggested that LA rinderpest virus can be stored stably for at least six years by freeze-drying in vial.
