Characterization of the M2e antibody response following highly pathogenic H5N1 avian influenza virus infection and reliability of M2e ELISA for identifying infected among vaccinated chickens.

In this study, the M2e antibody response was characterised in layer birds vaccinated and challenged with an Indonesian H5N1 virus isolate, using a single M2e peptide (sp-M2e) or four-branched-multiple-antigenic form of M2e (MAP-M2e) as antigens in two separate ELISAs. Anti-M2e antibodies were absent in chicks with high level of maternal haemagglutination inhibition (HI) antibodies and also in all layers vaccinated once, twice or three times with an inactivated commercial H5N1 vaccine. In contrast, anti-M2e antibodies were detected in vaccinated layers challenged with H5N1 virus and their presence was associated with virus isolation and an increase in HI titres. The number of birds that developed M2e antibodies, as well as the strength and duration of the M2e antibody response were strongly influenced by the length of the interval between vaccination and challenge. Birds challenged at six weeks after vaccination all developed M2e antibodies by 14 days that lasted until at least 56 days after infection. In birds challenged at two weeks after vaccination only a proportion of birds developed M2e antibodies by 14 days that lasted only until 28 days post infection. Both sp-M2e and MAP-M2e ELISAs had high diagnostic specificity but the diagnostic sensitivity of MAP-M2e ELISA was significantly higher and more effective in detecting M2e antibody in immune and infected birds. The results show that MAP-M2e ELISA would be useful for surveillance in countries using vaccination to control ...
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research