Evaluation of humoral immune response in puppies immunized to canine distemper with attenuated virus vaccine

Abstract

This study was carried out in order to investigate the kinetics of the immune response in puppies vaccinated to canine distemper, with attenuated distemper virus vaccine, by serum-neutralization test. Eleven healthy Beagle dogs, observed from birth to 30 months old, isolated far from other dogs, received monovalent living attenuated canine distemper vaccine at 75, 105 and 135 days old, and twelve months after the third dose of vaccine. Antibodies development were measured by serum-neutralization immediately before vaccination, at the 30th day after the first and the third dose administration, at the 90th day after the third dose administration, nine and twelve months after the annual dose. There was no canine distemper antibody detectable titer before primevaccination. The antibodies titer ranged from 4,047 to 4,880 neutralizing doses at the 30th day after the first dose administration and six months after annual dose, respectively. All dogs showed a similar response, although with variation, with antibody production of higher antibody titers than 2, which is considered the minimum protection titer. Twelve months after annual revaccination, the majority of the dogs showed high antibody titers, suggesting that annual revaccination could be unnecessary.