Meaning of Influenza A virus
Disease description:
My husband has had a high fever for the past two days and was diagnosed with influenza A after visiting the hospital. Could you please explain what “influenza A virus” means?
Doctor's answer (1)
Dr. Chen Tansheng
Influenza virus, belonging to the Orthomyxoviridae family, is an RNA virus. Its surface is enveloped by a lipid bilayer membrane studded with glycoprotein spikes composed of hemagglutinin (HA) and neuraminidase (NA). Based on antigenic differences in the nucleoprotein, influenza viruses are classified into three types: A, B, and C. Influenza A virus is highly prone to mutation—primarily involving variations in hemagglutinin (H) and neuraminidase (N) subtypes—of which 15 HA and 9 NA subtypes have been identified. Depending on the magnitude of antigenic variation, pre-existing human immunity may be either completely or partially ineffective against newly emerged mutant strains, thereby facilitating influenza epidemics.
