Immunization of cattle against rabies using inactivated cell culture vaccines.

Twenty-one heads of cattle were vaccinated with Madibovin, 31 with Rabdomun and 127 with Rabisin on 4 different farms. Rabies neutralizing antibody titre (> or = 0.5 IU/ml) was detected in 80% of 163 animals tested about 1 month and in 42% of 133 animals tested about 1 year after primary vaccination. On 3 of the farms 86 animals received booster vaccination about 1 year after primary vaccination. All these animals had antibody titre (> or = 0.5 IU/ml) about 1 month after booster and antibody levels were higher than after the primary vaccination. Rabies antibody titres (> or = 0.5 IU/ml) were detected in 96% of 50 animals tested 1 year after the booster. No significant differences (p > 0.05) in antibody levels were detected between animals vaccinated with Madibovin or Rabisin (farm C) respectively with Rabisin or Rabdomun (farm D) at any collection time. Responses to rabies vaccines varied considerably between the farms. After primary vaccination of the animals on 2 farms with the same batch of Rabisin, the antibody levels clearly differed (p < 0.0001) between the farms. Our results indicate that booster is always necessary after primary vaccination to ensure that all animals are protected.