What Is Influenza?
Influenza is an obligate parasite which can not reproduce by itself and requires a host to replicate. There are 3 types of influenza: Type A, Type B, and Type C. Type A Influenza’s can infect a variety of hosts, including birds, swine, horses, and humans. Type A and Type B are responsible for the seasonal flu outbreaks and they have the ability to genetically mutate to avoid the host’s defense mechanisms. We are probably all too familiar with the common flu symptoms: fever; sore throat, coughs, chills, and muscle aches. On the other hand, Type C influenza is responsible for non-seasonable mild illness in humans.
Type A Influenza
Let’s discuss Type A Influenza in a bit more detail. Type A Influenza strains are named based on the subtype of 2 important surface glycoproteins, hemagglutinin and neuraminidase. Hemagglutinin (HA) has 16 subtypes, H1-H16, and allows the virus to attach to and enter a host cell. Neuraminidase (NA) has 9 subtypes, N1-N9, and allows the mature virus to escape from the host cell after replication. Humans and swine are natural reservoirs for the following influenza Type A subtypes: H1, H3, N1, N2, and H2 (humans only). However, birds are a natural reservoir for all subtypes of Influenza Type A. The H5N1 strain of influenza (Type A) is the first known case of an avian flu being responsible for directly infecting humans.
Medical Resources for Influenza—Vaccines and Anti-viral Medication
What about vaccines and anti-viral medication? The annual flu vaccine is a trivalent vaccine – made up of 3 different influenza strains. Normally, the flu vaccine is composed of 2 Type A Influenza strains and 1 Type B Influenza Strain. Dr. Joe Duarte, a financial writer, stated that Novavax has 2 flu vaccines in early stages of development. However, we will need to isolate the exact strain of pandemic influenza from patients and then it will take between 6-9 months to have the effective pandemic flu vaccine ready for mass vaccination. On the other hand, Gilead and Roche and Glaxo Smithkline make Tamiflu and Relenza, which are 2 antiviral neuraminidase inhibitors. Neuraminidase inhibitors appear to have fewer incidences to drug resistance than the other class of antiviral medication, M2 ion channel inhibitors. Then again, Tamiflu was ineffective in treating some people infected with H5N1 avian influenza virus and its use has been speculated to lead to a more rapid mutation of the virus, according to Dr. Duarte.
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