An ELISA influenza A virus (NS1) antibody test to differentiate infected from vaccinated poultry.

摘要

Avian influenza (AI) vaccination in poultry would have greater worldwide acceptance if a reliable test were available that discriminated between naturally infected and vaccinated-only birds (DIVA). Nonstructural protein (NS1) expressed in AI infected cells is not packaged in the virion and therefore could be used in an ELISA differential diagnostic test. To differentiate AIV-infected chickens from those immunized with an activated AI virus, we developed an ELISA test with recombinant nonstructural protein (NS1) as the diagnostic antigen cloned from an AIV H9N2 subtype strain expressed in Escherichia coli. Serum was taken from vaccinated and infected poultry and screened for anti-NS1 antibodies to AIV. NS1 protein was detected only in experimentally AIV infected chickens.