Five 3-day-old oolost-um-deprivM piglet were inooi1atl intranasally with ateriuaerl 10 stain, with a tier of 10”5.3 TCIDS0. They exhibierl no symptoms for one week aft inoculation.
One 40-day-old olc6t-un-degiv1 pig was incculaed intanasally with the ateriuaeri 10 stain 3 times It had antibody tier of 256x.
Four 40-thy-old cxlcGtum-deprivM pigs were incculatM intanasally with the atenuaal 10 stain, having and inf±ve tier of 1(Y’5.3 TCIDSO. After 5 days they
were challenged with the virulent CN Stain, having an infative tier of 1COLDSO. Two days laer the pigs showed diarrhea for two days only.
The virus cxzild bo dewed in nasal and kal swabs obtainer! from the pigs two days aft intanasal inoculation with the atenuai 10 stain by Fluorescein antibody technique.
In 30-day-old SPF pigs incculaerl with the atenuaerl 10 stain (10^7 TCID5O) and Kept at 18~20'C, could ke proeced against the virulent virus CN strain (100LD5O)Challenged on 5 days after inoculation.