Albert Einstein, surely one of the most remarkable humans who ever existed, said “I have no special talent. I am only passionately curious.”. While I would hardly compare my intellect to Einstein’s, I too have always been curious, and keen to learn new things. Retirement has given me the opportunity to do a lot more reading on numerous subjects, though it is surprising what other activities have also emerged to fill my days! Then along came COVID.
Viruses are fascinating things, if unimaginably tiny: about 600 SARS-CoV-2 virus particles laid end-to-end would only stretch as far as the width of a human hair! Some would not even consider a virus as a living thing , relying completely, as they do, on the molecular mechanisms of another organism for their reproduction. The virus that causes COVID-19 can only be seen using an electron microscope and contains 15 genes , compared to the 30,000 genes in humans. The RNA (genetic material) of SARS-CoV-2 is wrapped in an icosahedral protein shell. The viral envelope consists of a lipid bilayer in which the membrane (M), envelope (E) and spike (S) structural proteins are anchored. The average diameter of virus particles is around 125 nm. The diameter of the envelope is 85 nm and the spikes are 20 nm long. On average, a coronavirus particle has 74 surface spikes.
There are 4 human coronaviruses that produce symptoms that are generally mild, and continually circulate in the human population. They are responsible for around 15% of common colds. There are now 3 human coronaviruses that produce symptoms that are potentially severe: Middle East respiratory syndrome-related coronavirus (MERS-CoV), Severe acute respiratory syndrome coronavirus (SARS-CoV), and Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
SARS in 2003 infected more than 8,000 people, killing about 10% of these. MERS was first identified in 2012 and it has caused a few outbreaks since then. As of December 2019, 2468 cases of MERS-CoV infection had been identified, of which 851 were fatal. According to the European Centre for Disease Prevention and Control , as of today there have been 5,175,476 confirmed cases of COVID-19 (the disease caused by SARS-CoV-2) and it has caused 338,039 deaths!
It seemed to me that something this tiny, that had killed so many people, and threatens to cause a Global Depression to rival the one in the 1930s was worthy of my curiosity.