Attempis were made to study the sbi1ition of the Latinil Hog Cholera Liquid Vaccine. The result were summarii as follow: UtiI1 Hog Cholera Liquid Vaccine was godiel from spleens and lymph nodes of rabbit infected with LFC strain of hog cholera virus. The fresh prepared vaccine had a 50% goteztive dose of 10^4.5PD50/gm when titrated in pigs, where as the vaccine aft nine-month peservation in refrigerator at 2-5? had only a level of 10^2.22PD50/gm.
Rabbit inoculated with 1O^-6 dilution of fresh vaccine still showed a typical curve of fever reaction. The virus titer of the vaccine dropped to 10^3.5RID/gm, after an inter valof nine months when titrated in rabits.
Two to four rabbits were intravenously inoculated with 2 ml. of vaccines at various duration of peservation, respetively. Temperature of each rabbit was checked twice a day, in the morning and afternoon, for ten days. Typical fever reaction (temperature rise upto4l.1? or higher) wereobseralin 14 out of 16 rabbit (87.5%). The temperature curve was almost the same as that of oontrol group.
This typical curve of fever reaction caused by vaccine inoculation was not influenced by duration of vaccine eservation. The temperature rose to peak (41-41.8?.) on the 2nd or 3rd daylc then declined to normal range on the 4th day after incailation. A second fever (40.1-41) was observed at S or 6 days after the inoculation. The first peak of fever was higher than the snd. This phenomenon was called “diphasic temperature curve’ Twelve otu 16 rabbits showed this reaction.
The Lztinized Hog Cholera Liquid Vaccine peserved in refrigerator (2-5?.) were tested for pctcy at various durations, i, e, from one week to nine months. All inoculated and control pigs were challenged with the virulent bkxd (AU) strain) at dcseofl(Y’S MID onthe 10th day pcst-incculation. All pigs were observed for clinical signs for 3 weeks. All the vaccinated ones survived, whereas the controls died of the challenge.
The PH of the fresh prepared vaccine was 5.4. No any PH change was notl during various times of the nine months preservation.