INFLUENCE OF VACCINATION OF PIGS WITH DELETED AUJESZKY'S DISEASE VACCINE ON THE EXCRETION OF VIRULENT HERPESVIRUS SUIS TYPE 1 AND INTENSITY OF LUNG LESIONS AFTER CHALLENGE

摘要

Influence of pig vaccination against Aujeszky's disease (AD) on the level of virulent Herpesvirus suis type 1 (SHV-1) excretion as well as on intensity of lung lesions after challenge was evaluated. Eighteen 8-week-old piglets, divided into 3 equal grups were used. Two groups were vaccinated twice in age of 12 and 16 weeks with deleted Porcilis Begonia vaccine at doses of 2.0 ml (10~(6.0) TCID_(50)) administered intramuscularly (I.M.) - group I or 0.2 ml (10~(5.0) TCID_(50)) administered intradermally (I.D.) using needleless apparatus -group II. In group K (control) 2.0 ml PBS was given I.M. Seventy days after the first vaccination all pigs were infected intranasally with 10~(5.5) TCID_(50) /ml dose of virulent Northern Ireland Aujeszky-3 (NIA-3) strain. During 10 d post infection (d.p.i.) and on the 21st d.p.i. the nasal swabs were taken. SHV-1 tilers as -log_(10) TCID_(50)/100 mg of nasal secretions were expressed. Lung lesions were also evaluated after slaughtering the pigs on the 21st d.p.i. Vaccination of pigs with deleted AD vaccine, irrespective of administering route, radically restricted the extent and duration of virulent SHV-1 excretion after challenge. The vaccination considerably reduced the extent and intensity of inflammatory lesions in lungs, what prove the high protective value of the vaccine in restraining secondary bacterial infections in the respiratory airways.