Antibody response to an inactivated vaccine for rhinotracheitis, caliciviral disease, and panleukopenia in nondomestic felids

The efficacy of an inactivated vaccine for the prevention of feline viral rhinotracheitis (FVR), feline caliciviral disease (FCVD), and feline panleukopenia (FPL) was tested in 27 nondomestic adult felids from 7 species. The vaccine was given IM at the standard domestic cat dose in 19 animals and double this dose in 8 others. The animals were vaccinated either 1, 2, or 3 times. Serum-neutralization (SN) antibodies to FVR (mean SN titer, 23) developed in all 15 animals that were previously seronegative, and SN antibodies to FCVD (mean SN titer, 11) developed in 19 of 21 animals that were previously seronegative. There was no significant increase of SN antibody titers by doubling the vaccine dose or by administering a 3rd vaccination. The optimal response could be obtained by using the domestic cat vaccination protocol of a single dose given twice, 4 weeks apart. The critical evaluation of the SN antibody titer for FPL was complicated by preexisting titers to FPL from previous vaccinations, but in 23 animals the titers became higher, whereas they remained unchanged in only 4 animals. The persistence of the SN titers was evaluated 7 to 9 months later and found to be satisfactory for FVR (mean SN titer, 18) FCVD (mean SN titers, 43) and FPL (mean SN titer, 517). Enhanced persistence of titer could not be demonstrated by doubling the dose or administering a 3rd vaccination.