142 - Influenza Virus Attack

Abstract

Influenza is an acute infectious illness of viral etiology that primarily affects the respiratory tract. The virus is prone to frequent mutations, which leads to genetic “drift” of the virus and subtle changes in the immunogenicity of the virus nearly every year. Because of the high mutation rates, vaccination against influenza commonly provides protection for only a few years or less. The segmented structure of the virus also facilitates occasional genetic reassortment of the virus and alterations in the major hemagglutinin (HA) and neuraminidase (NA) surface glycoproteins, called genetic “shifts.” These genetic shifts and antigenic variations lead to the genetic diversity of type A. Major antigenic shifts underlie the development of worldwide pandemics, such as those of 1918, 1957, 1968, and 2009. There is a direct relationship between preparedness for seasonal influenza and preparedness for pandemic influenza. There is a need to unify these two approaches to optimize our readiness for a pandemic. High rates of community vaccination against influenza are an important mitigation strategy against influenza. Establishing population immunity to influenza will also aid in distinguishing it from the more deadly biological agents that have a similar initial presentation. Influenza impacts certain segments of the population disproportionately, especially persons with advanced age and medical comorbidities; the demographic changes in society of an aging population, and an increase in the number of patients with chronic medical concerns means that the health effects of a potential influenza pandemic may be even more pronounced. There should be mechanisms to ensure adequate supply of antiviral medications, currently unlikely to be able to meet prolonged demand with the existing infrastructure of vaccine delivery.