Long-term immunity in cattle vaccinated with a recombinant rinderpest vaccine
Inui, K.; Barrett, T.; Kitching, R.P.; Yamanouchi, K.
Veterinary Record 137(26): 669-670
1995
ISSN/ISBN: 0042-4900 PMID: 8966974 Document Number: 447933
A recombinant vaccine was constructed by inserting the H gene of rinderpest virus (RPV) into the attenuated vaccinia virus (VV) LC 16m0 strain. Four calves (10 months old) inoculated with the recombinant vaccine developed virus neutralizing antibody to RPV and ELISA antibody to VV. Antibody levels in monthly blood samples remained constant for one year after vaccination when the calves were challenged s.c. with the virulent Saudi 1/81 strain of RPV. A marked anamnestic response to RPV occurred without viraemia or leukopenia. All 4 calves were protected clinically against the challenge. An unvaccinated control developed rinderpest and died after challenge and RPV was transmitted to an in-contact calf. Virus excretion by vaccinated animals after challenge could not be excluded since one of 4 control in-contact calves died from RPV. Since there were no clinical signs of RPV in the challenged calves it is suggested that the more likely source of infection was the virus secreted by unvaccinated, challenged controls housed adjacently. Further studies are planned to determine the persistence of the immunity conferred the recombinant vaccine.