I wanted to take a little time to go into some of the science behind what is going on with Covid-19.  Some of you may be at greater risk from dying from boredom here than Covid but bear with me.

A feature of these novel Corona viruses (SARS, MERS, Covid) is that they tend to affect the immune system in detrimental ways making it difficult to clear them.  These viruses have proteins on their outer coats that can bind to lung receptors (ACE2).  Essentially they have the correct three dimensional structure, similar enough to human proteins, to fool the body.  They have ‘the key that fits that lock’.  

Through similar mechanisms they can also enter immune cells known as T-cells.  You may have heard of this particular immune cell since it is also the cell that is invaded and compromised in HIV infection.

The immune system has three main components; the Innate (most primitive and first line of defense), the Humoral (think antibodies) and the Cellular (T cells) immune system. 

A T-cell can be thought of as the ‘general’ of the army.  It is responsible for coordinating the Innate and Humoral systems for just the right kind and intensity of response to an invading organism.  Uniquely (and similarly to HIV) the virus enters T-cells and kills them.  In the absence of T cell direction the regular army runs amuck.  I’m trying to be cautious with the analogy but the Army is out of control.  The country side is attacked and pillaged and massacres occur in many villages (like the lungs).  Under normal circumstances viral pathogens are cleared with just the right amount of force, maybe a ‘surgical strike’.  These novel Corona viruses produce a carpet bombing scorched earth policy.  In a case of mistaken identity, our own immune system kills us in this particular infection.

This is why certain drugs with immuno-modulatory effects (Hydroxychloroquine and Azithromycin) can help in this infection by doing some of the work the general might have in telling troops to ‘stand down’.  However this does not mean you need to stockpile these medications because they can only be used in hospital settings for the sickest patients.  Please save them to be used appropriately by the right people for the right people. 
 
Thanks for your attention.  There will not be a quiz;)  I hope this sheds a little light on why these atypical Corona viruses are so virulent.  Stay Home, Stay safe.
 
Warm Regards,
 
Dr. Nick