Abstract:
ln Sri Lanka, the first dose ofpre-exposure antirabies
vaccine is given to puppies at the age of3
months with annual boosters. There have been
many instances where puppies of less than 3
months have been affected with rabies. Antirabies
vaccination failures have also been
reported. Therefore, it is important to know the
duration of protection in dogs following antirabies
immunization.
Animals for this study were divided into two main
groups (adult dogs and puppies) and further subdivided
into 4 groups (adult dogs with a past
immunization history against rabies, adult dogs
without a past immunization history puppies of
immunized bitches and puppies of unimmunized
bitches). ln this study, neutralizing antibody titres
in puppies and adult dogs following pre and post
anti-rabies immunization were detemined by the
rapid fluorescent focus inhibition test.
All animals were bled on days 0 (Do preimmunization),
30 (Dro), 180 (D,ro) and 360 (Druo).
Titres were less than 0.5 IU/mL (protective
antibody titre against rabies) in Do samples of all
puppies recruited for this study, in 26.7Yo of D.o
samples of puppies of unimmunized bitches, in
89.5%o of D,ro samples of puppies and in all Druo
samples of puppies. Antibody titres in 50% of
Druo samples of adult dogs without a previous
immunization history were also less than 0.5 ru/
mL. Antibody titres of all dogs with a past
immunization history against rabies, were
maintained above the protective level I year after
immunization.
