Pigs with 8 weeks of age were vaccinated with live vaccine of LEC-China stain intramuscthrly (N) or intanasally (IN). All pigs vathnatui IN were sick and dead, and all pigs vathnagerl TM survived when they were challenger! with a virulent strain 10 days aft vaccination. Result implied that LPC-China strain could not replicate so well at lower temperature condition.
Primary and estublished cell lines originated from pig kidney and testicle were used for serial pessage of LEG-China stain virus. Result showed that a titer of 10”6,5 TCIDSC?n1 and 1O”7,3 RIDSOhnl could ke reached when the tirus was propagated in tunmary PK-CL cell line. The virus, however, replicated poorly in nimary swine kidney, testicle cell cultures and in ESK, ST-CL estublished cell lines. The virus replicated ketter at 3ltD.
Dc€es of 1/1(0, 1/1,(U) and 1/5,(U) of the virus which has &en serial passagerl6 times in PK-CL cell line, was incculated TM in 8-week old pigs with low neutralizing anthcdy. All vaccinated pigs survived with a febrile reaction (over 4112) when they were challenged 10 days after vaccination; on the other hand, all unvathnated control pigs were killed afgter challenge