Relationship of the Intensity of Infection to the Complement Fixation Antibody Titer at the Time of Infection Made with Attenuated Rinderpest Virus

Abstract

Relationship of the intensity of infection to the CF antibody titer at the time of infection made with attenuated virus was investigated by the author availing himself of the following 3 occasions in order to facilitate the selection of the virus strain to be attenuated for the use of vaccination and the decision of the amount of serum for the simultaneous inoculation of live virus and immune serum.
1. Simultaneous inoculation made on the calves of the Japanese black cattle with lapinized and avianized rinderpest virus (La strain) with varying amounts of immune serum.
2. Calves of the Japatese black cattle inoculated with the LA strain and those inoculated with the avianized rinderpest virus of bovine strain (BA strain) which has a stronger pathogenicity.
3. Inoculation of the same attenuated virus strain on the cattle of different resistance against rinderpest virus, namely, the inoculation of LA strain on the calves of the Japanese black cattle and adult black cattle and the inoculation of BA strain on the calves. of the Japanese black cattle and the calves of Holstein-Friestian. The results obtained were as follows:
I. On comparison of the calves receiving the simultaneous inoculation of LA strain and immune serum and those receiving LA strain alone, the latter were found to show more frequently the inoculation reaction and a greater “fever volume” of Nakamura et a1 and the result of complement fixation test showed that they possessed a higher rate of CF positive reactors with higher means of highest FT value and longer duration of the CF positive period.
As for the animals of simultaneous inoculation, the rate of inoculation reaction and the difference in the amount of fever volume were not recognizable. The smaller the amount of immune serum used, however, the rate of positive reactors was higher with higher means of highest FT value and longer duration of the CF positive period.
Challenge made with highly virulent strain of bovine origin on a part of the calves, receiving the single inoculation of LA strain and those receiving the simultaneous inoculation of LA strain and immune serum showed that the former had complete resistance against the challenge while in the latter case there were some which showed inoculation reaction and the changes in FT value after challenge though they presented the outward appearance of complete resistance. This intensification of FT value after challenge was; stronger amcng the animals receiving larger amounts of immune serum.
2. Calves of the Japanese black cattle receiving the inoculation of BA strain, in comparison with those receiving the inoculation with LA strain, showed a higher rate of inoculation reaction, larger amount of fever volume, higher means of highest FT valueand longer duration of the positive period.
3. On comparison of the calves and adult Japanese black cattle receiving LA virus, the former showed larger fever volume, higher means of highest and longer duration of CF positive period.
As for the calves of the Japanese black cattle and those of Holstein both receiving the inoculation of BA strain alone, the former showed more frequently inoculation reaction, larger fever volume, higher means of FT value and longer duration of CF positive period.
As for the calves of the Japanese black cattle and those of Holstein both receiving of BA strain alone, the former showed more frequenty inoculation reaction, larger fevervolume, higher mean of FT value and longer duration of CF positive period. In view of the findings stated above, it is concluded that the intensity of infection runs in parallel with the CF antibody titer and the duration of CF positive period when. inoculation is made with attenuated rinderpest virus.