Soon after the new influenza H1N1 strain emerged in April 2009, I began a series of blog posts on basic aspects of influenza virus replication and pathogenesis. The goal of this series is to provide information that will allow everyone to better understand the events surrounding emergence and spread of the new pandemic strain. Unfortunately …
In response to viral infection, many organisms mount a remarkable defense known as the immune response. This response to viral infection consists of an innate, or nonspecific component, and an adaptive, or specific defense. The innate response is considered the first line of immune defense because it is active even before infection begins. In fact, …
When influenza virus is introduced into the respiratory tract, by aerosol or by contact with saliva or other respiratory secretions from an infected individual, it attaches to and replicates in epithelial cells. The virus replicates in cells of both the upper and lower respiratory tract. Viral replication combined with the immune response to infection (which …
Now that we have a rudimentary understanding of influenza virus replication, we can begin to consider how the virus causes disease – a field of study called viral pathogenesis. The first step in this process is virus entry into the body. The human body is covered with skin, which has a dead outer layer that …
