How to differentiate between type A and type B influenza

Both influenza A and influenza B viruses are among the three major subtypes of the influenza virus, and they exhibit significant molecular and structural differences. The hemagglutinin gene of the influenza A virus has unique coding and expression characteristics. In immunological detection, it is a virus with distinct molecular markers; its hemagglutinin glycoprotein structure differs from that of influenza B virus, providing a basis for differentiating between the two. Additionally, the extranuclear genome of the influenza virus serves as another distinguishing criterion: influenza A virus possesses only one extranuclear genomic RNA species marker, whereas influenza B virus has two such markers. Thus, the structural features of their extranuclear genomic RNA are clearly distinct, aiding in the differentiation between influenza A and influenza B viruses.