Historic Influenza Perspectives on an Influenza Pandemic

Abstract

Before discussing the issues related to influenza pandemics, it is necessity to understand the mechanisms that underlie the variability, of the virus. The influenza virus, like most RNA viruses, is genetically highly variable and this variability gives rise to a constant changing of the antigenicity of the virus. This, in itself, is not peculiar to influenza. However, what is unique to the virus is that this antigenic changeability constantly gives rise to new,strains of virus which are able to escape the immunity which the population builds up to the predecessor strain. The epidemiology of influenza is thus characterized by the constant advent of new antigenic strains of the virus giving rise to recurring epidemics of infection.