Production of Recombinant Neuraminidase NA Protein of Influenza A/H5N2 Virus and Its Application for the Detection of Virus-Specific IgG to Influenza A Viruses.

The major antigens of the influenza virus are the surface glycoproteins hemagglutinin (HA) and neuraminidase (NA). Antibodies to HA are virus-neutralizing, whereas NA-specific antibodies alleviate the severity of the infection while also conferring protective immunity. In cases of genetic drift or antigenic shift among circulating influenza strains, anti-HA antibodies may show reduced cross-neutralization efficiency. Therefore, when assessing susceptibility to influenza following infection or vaccination, it is crucial to consider immune responses directed against the second principal antigenic component, NA. NA-specific antibodies have been demonstrated to possess cross-reactive and protective properties. We obtained a recombinant NA protein of influenza A virus and used it for the detection of virus-specific IgG to influenza A viruses.