In order to how the bust uoperities of passaged - Lapiniad Hog Cholera virus of rabbit kidney cells, the pathogenicity and immunogenicity were studies. The result axe as follows;
Pyerctic responses were studied in rabbit inccu]at! intravenously with HC LPC 820 th rabbit - passaged and RK - LPC 10th passage viruses. Significant pyre - ctiv response was ovsererl 70 hours after inoculation in the rabbit inCCWaIed with RK - LPC virus.
The same viruses were also tested in pigs, but no pyrectic response after i - ncculaJ withRKLPC l0thvnisoraftrbuingchalleagelwith5 ml(1:10)ofvirulentHC ALD bkxDd virus, was not! their appetites were normal, and there was no leucopenia orshifttotheleftintheneutrophils inthetestipigs,
onsils spleen, mandibular lymph ncdes, mesentric lymph ncdes and inguinal lymph ncdes werefoundtobyvirus ptcitiveonday4 aftrincculation. From4 thtol0th days all tests on the tonsils efoundtolreviruspc6itiver The big- best viral titer 1&’3.OTCflJSCVg, was ketweenthe’7thand 8thdays.
The result after 10 reverse passages in pigs, revealed no abnormal clinical signs or Summary shift in the neutropils or virus shedding in urine. However the WBC count showed slight, but in significant decrease.
Thecrcs meutralizationtestof HcLFkD, RK- LPC lOthand 15 thviruses, usingthe antiserum of homologus and hetrogous BVD T20 -5 viruses, sho’it! bight SN antibody titers able to neutrali several types of Hog Cholera viruses. It also showed the HC A’76 virus, HC field isolat! chronic soup B Kanagawai74 vinrus, HC atenuat! (WE- and HC RK - LEC viruses. Therefore no antigenic difference in the crcs immunity was found.
the immunogenicity of RK-LPC 20th passaged virus had a potency of 1C’-3.5 in the test pigs. The pig with serum neutralization (SN) titer, 1:4 resist! the challenge with 1QCOJ MID of HC AL]) virulent blood virus. Pigs with titers of 1:2. however, died after the challenge. Pig with maternal antibody titer of 1:4 showed an increase of SNanti&dy2weeks later. However pigs with maternal titers of 1:8 and 1:16 showed an increase atE weeks. But the SN antibody titers reponse was not consent at the titers of 1:32.
The immunthi pigs were challenged from 2 to 6 days after immunization. Pigs challenged on the 5th and 6th day after inoculation surived with no abnormal reactions,