Introduction
The flu is a contagious illness that can cause mild to severe symptoms and even lead to death. Despite the widespread use of vaccines, influenza viruses cause seasonal epidemics and affect up to 20% of the U.S. population every year. The CDC estimates that up to 200,000 people are hospitalized, and 36,000 people die from flu-related causes annually. One of the reasons that influenza is so prolific is that it tricks our bodies into reproducing the virus by the millions.
Influenza Replication
Once the influenza virus enters our body, usually through the intake of coughed or sneezed infected droplets, it enters our cells and uses the cell resources to reproduce itself. The virus enters a host cell by first attaching itself to receptors on the cell membrane. The cell membrane then folds inward in a process called endocytoses, which causes the flu virus to sink into the cell until it is completely wrapped in a membranous "bubble". The viral package then breaks free of the membrane and is transported within the cell where the viral contents are eventually poured into the cell's cytoplasm (Stanford University, 1999).
The influenza genetic material migrates to the nucleus of the cell where the cell's own genetic material is contained. From the nucleus, the viral genes take over the cell's productivity, and instead of generating new cellular material, the cell produces multitudes of new virus particles. These viral components assemble themselves within the cytoplasm of the cell to form new influenza viruses, which are eventually released into our systems to infect other cells in the same manner (The National Health Museum).
Stopping Viral Reproduction
Understanding how the flu virus enters our cells and the process by which it reproduces is essential for developing treatments and vaccines. Medical researchers have studied the influenza virus more than any other and as a result have developed some measures to interfere with the viral life cycle. Antiviral drugs can interrupt the process of viral replication at several different stages. Agents such as Tamiflu can stop newly formed viruses from being released from the cell. Other such medicines prevent the manufacture of viral proteins or stop the virus from being emptied into the cytoplasm once it is taken into the cell.
The success of antiviral drugs is dependent upon early diagnosis. They are only effective if administered within a day or two after the onset of illness, and their primary application is to prevent the spread of disease for individuals that have come into contact with an infected person. Researchers seek to further understand the elusive and ever-changing flu virus in order to develop better drugs and vaccines that are effective for all types of influenza (Cornell University, 2005).
