Potency test of inactivated Newcastle disease vaccines by monoclonal antibody blocking ELISA.
The potency of 27 different inactivated Newcastle disease (ND) vaccines was determined by immunization and challenge tests. Three- and four-week-old SPF chickens were immunized with 1/50 dose of vaccines. The chickens were bled and challenged three weeks later. The protected/challenged ratio was determined. Serum samples were tested by the haemagglutination inhibition (HI) test and by a monoclonal antibody (MAB) blocking enzyme-linked immunosorbent assay (B-ELISA). Ninety-four percent of the vaccinated chickens (353 birds) with a B-ELISA value above 60% were protected. A strong positive correlation (0.934) was found between 'actual protection' (protection against challenge) and 'estimated protection' (protection calculated from the B-ELISA results). Based upon the results obtained, this B-ELISA seems to be suitable for replacing the challenge test in the potency control of inactivated ND vaccines in the future.
Horváth
E
E
State Control Institute for Veterinary Biologicals, Drugs and Feeds, Budapest, Hungary. herno@oai.hu
Czifra
G
G
Nagy
E
E
Engström
B
B
Mérza
M
M
D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology*; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D000914:Antibodies, Viral / Q000097:blood; D002645:Chickens; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006385:Hemagglutination Inhibition Tests; D006387:Hemagglutination, Viral; D009521:Newcastle Disease / Q000517:prevention & control*; D009522:Newcastle disease virus / Q000276:immunology*; D014611:Vaccination / Q000662:veterinary; D015164:Vaccines, Inactivated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D015164:Vaccines, Inactivated; D014765:Viral Vaccines