Influenza is an acute infection caused by the virus classified within the family Orthomyxoviridae which mainly affects our respiratory system but has generalized manifestations also. The infection is mostly seasonal and is mainly caused by the Influenza-A virus and sometimes the milder variety by the Influenza-B virus. Although, in common practice, the word “flu” is universally applied to every disease which has cold and cough symptoms and is often misleading in context to the type of disease.
On the surface of the virus are Glycoproteins (proteins that contain oligosaccharide chains attached with the amino acid side-chains) known as Haemagglutinin (H) and Neuraminidase (N). As these can undergo variation, so we get influenza of variable intensity from time to time. Now let us understand this: if there is a minor change in haemagglutinin, it is known as ‘antigenic drift’; however, if there is a major change in....
