EFFECT OF VACCINAL AND PASSIVE-IMMUNITY ON EXPERIMENTAL-INFECTION OF PIGS WITH PORCINE PARVOVIRUS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 41  (9) , 1368-1371
Abstract
One group of 5 pigs was vaccinated twice at 6 and 8 wk of age with an inactivated porcine parvovirus (PPV) vaccine. A 2nd group of 5 pigs was passively immunized at 9 wk of age and a 3rd group of 5 pigs served as nonimmunized controls. The immunity of all pigs was challenged with live PPV at 10 wk of age. Four vaccinated pigs with hemagglutinating-inhibiting (HI) antibody titer of 160-640 and 3 passively immunized pigs with HI titer of 80-160 were resistant to PPV infection. Neither infective virus nor viral antigen was detected in their tissues. The virus replicated in tissues of 1 vaccinated and 2 passively immunized pigs with HI titers of 80 and viral antigen was detected in their lymphoid tissues. There was a 4-fold increase of HI titer in 1 passively immunized pig. Viremia and viral excretion were not detected in any of the vaccinated or passively immunized pigs. PPV replicated in the tissues of nonimmunized pigs; virus and viral antigen were detected in their tissues and they produced HI antibodies to PPV. All nonimmunized pigs developed viremia and shed virus in oral secretions and feces. The data show that a high level of humoral antibodies is required for protection from PPV infection.