How to differentiate between type A and type B influenza

Influenza A and influenza B are two distinct types of influenza viruses, differing significantly in morphology, viral sequences, and virological serology. Influenza A is a semi-filamentous virus with hemagglutinin of type H1 or H subtype, and its serological markers are type I1 or I subtype. Its genomic structure primarily consists of the classical A and B subtypes, although a few other subtypes also exist. Influenza B is an oval-shaped virus, with hemagglutinin also classified as H1 or H subtype and serological markers as I1 or I subtype. Its genome typically comprises the classical A and B subtypes, along with some less common types such as C, D, E, and F. Both influenza A and B viruses pose varying degrees of harm to humans; therefore, it is essential to differentiate between them in order to implement the most appropriate preventive measures.