Where did this virus come from?
There are rumors that it started in a lab, or that people caught it from animals
at a market. While we don't know exactly, the virus appears to be a natural mutation of an animal virus. Not likely from
a lab either in China or by the US Army. The viral genetics can be traced back to bats with mutations occuring naturally rather
due to laboratory manipulations.
There are many viruses that are common in animals but do not infect
or do not cause disease in humans. Some of these animal viruses and their similarity to human viruses have been used to develop
vaccinations such as the cow pox vaccine developed to lend some immunity to small pox (which was more deadly). But, with a
little mutation or genetic change some safer viruses can become dangerous. Influenza viruses that start in animals, like swine
flu, avian flu Or HIV (which moved from chimpanzees to humans) and other diseases sometimes move across to cause human disease.
coronaviruses have crossed over to cause human disease in the past couple of decades. The first is the SARS-CoV in 2003 thought
to have crossed from chickens. SARS caused a serious pneumonia and had a 15% mortality rate- probably the reason it did not
cause more disease since a balance between disease and death has to have a lower death rate in order to spread significantly.
Then we had MERS CoV which we believe crossed from camels and also had a high mortality rate ~30%. Those viruses did
not stick around or spread enough to have a serious effect on our nation.
But now SARS-CoV-2, the current virus causing
COVID-19 disease, has an estimated 3.4% mortality and therefore is likely to infect much greater numbers (some estimate 80%
of us will be infected before COVID-19 runs out.)
The bad news is that we have a highly infective disease with a relatively high
(compared for example to the flu) death rate, that is yet low enough to allow the continued spread of the disease. We need
a coordinated and effective response. Stay at home, stay well.