73 - Virus- the great undead.

KYJ 73 - Virus the great undead.

Of recent years there has been a Hollywood buzz topic explored in a few films. The Zombie apocalypse.  You know the plot. A creature or creatures that were neither dead nor alive sought human hosts with which to inhabit, biologically enslave and ultimately conquer.

Sound familiar?   We already have a zombie apocalypse on our hands.  It is called the Flu.  It is called Herpes.  It is called HIV, or Hepatitis, or croup or the common cold.

All these diseases are caused by a non living yet not dead particle called a Virus.

Viruses are protein shells with a single strand (usually) of genetic matter. Typically, they are very very small when compared with human cells.  Eg  If a white blood cell was a 50m Olympic swimming pool, a virus by comparison would be a 2 year old child swimming in that pool.
We're talking small.

A virus is incapable of reproducing itself (the definition of a living organism is that it can reproduce), so it is not considered alive or living.  It is either active or inactive.
To replicate a virus attaches to a host cell.  It bonds with the membrane of the cell and expels its genetic (RNA) material inside the cell.   The genetic code penetrates the host cells own DNA, joins to it and reprograms the cell to cease being what it was before infection, and become a factory to manufacture more viral particles.
It's a zombie.

Let's look at a Flu virus- Influenza A.  "Flu" has many surface proteins that are categorised as Hs and Ns.  You've heard of H5N1, or H1N1 flu, bird flu, swine flu?

The H is a protein called hemagglutinin and it is responsible for letting a virus stick onto and penetrate a cell.

The N is a protein enzyme called Neurominidase which is responsible for the release of a new viral particle from a host cell.

When you have the vaccination for flu, you are getting the Antigen (signature of a weakened virus).  Your immune system then makes antibodies to "attack" the real infection flu virus when it invades you in the flu season.  The Antibody actually attaches to the H disabling the virus and stopping it from endearing and infecting the cell.

Anti viral drugs (Relenza, Tamiflu) in converse attack the virus's N protein, stopping the newly created viruses from being released by the slave cell.

Signalling invasion by a virus the cell releases a chemical scent (cytokines) called interferon, that calls macrophages (white blood cells) to destroy the infected cell.

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These viruses are tricky wee things.  Small, un-dead, efficient killers that inhabit the bodies of cells and convert them into slaves.

Zombies to the max!!