THE INFLUENCE OF SPECIAL ANTIBODY TO THE LMMUNITY OF NEWCASTLE DISEASE VACCINE

The influence of special antibody to the immunity of Newcastle Disease vaccine was studied. The vaccine I combined with anti-NDV antibody coming from chick was secretity to 1 old or 28 old chickens whether they had antibody or not, and can induce high humoral immune response. At 14 days after immunization, the protection rate after challenged with virluent Newcastle Disease virulence(NDV) was 100%. The hatchability and mortality of chicken in day 8 of age did not been affected by the vaccine I which combined with special antibody. At day 14 of age the HI title of antibody in the chickens was 5 log 2 or so, and the rate of protection after challenged was 80%～100%. The titles of antibodies in the tested chickens immunized with the inactivated oil-adjuvant vaccine combined with special antibody(ND-OIC) were higher than the inactivated oil-adjuvant vaccine(ND-O). The results showed that the special antibodies can enhance the security of vaccine I and do not affect the immunity ; ND-OIC can induce high humoral immune response.