ISSN:
1432-8798
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Serial passage of bovine ephemeral fever virus in hamster lung cells, HmLu-1, deprived rapidly the virus of virulence for cattle with simultaneous loss of the ability to produce neutralizing antibody. The attenuated virus thus obtained, however, could prime cattle to produce neutralizing antibody rapidly to high titers following a subsequent inoculation of formalin-inactivated, AIPO4 gel-adsorbed vaccine (K). Although one subcutaneous dose of live vaccine (L) prepared from the attenuated virus produces no detectable amounts of neutralizing antibody unless as heavy a dose as 107 TCID50 was used, the priming effect of L vaccine was shown even with 10 TCLD50. Similar priming effect was also shown in mice by intracerebral inoculation of L vaccine. Maximal antibody response of cattle was obtained by one subcutaneous L vaccine dose of ≥ lO5]TCID50 followed by 3 ml of K vaccine administered intramuscularly at intervals of 2 to 4 weeks. This LK method induced seroconversion in nearly all of initially seronegative cattle, and the neutralizing antibody thus produced persisted much longer than that following two doses of K vaccine given at one-month intervals. The LK method exerted little side effects in cattle. Cows vaccinated during pregnancy delivered healthy calves in term. No adverse effect on milk production was shown. The vaccine virus could not be passaged serially in calves by intravenous inoculation of the blood. Lyophilized L vaccine was stored at 4
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01250220
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