Coronavirus is a respiratory virus that we've had in human populations for
as long as there have been humans. It is possible for there to be new
coronaviruses when somebody is around an animal that has an animal version of
coronavirus and then it's able to mix with a human coronavirus and
create something new kind of like how influenza can do that. But then the
challenge becomes that it's a new virus and so the human immune system hasn't
seen that virus before and so then people are more likely to be contagious
because they don't have a natural immunity already built up from prior exposure.
So I think that's why we're seeing this new corona virus moving
quickly through different populations. We definitely saw that in China in that
city and area of China where many people got infected very quickly, and then as
this coronavirus has moved into different populations, then that process
has then started to play out again, and the example of that would be in
Italy where we're seeing widespread coronavirus infection because people
don't have immunity so it's more likely to spread through the community.
And also I think in many other countries now we're seeing widespread coronavirus.
Also here in the United States, we're having spread particularly
in Washington, California, New York City, for similar reasons: somebody has
the virus and is exposed to somebody that's not immune and then the virus is
likely to spread. The way the virus spreads is as we have thought before,
and like other corona viruses, it's a respiratory virus. So coughing, sneezing, it's in
our phlegm and in our sputum. We think primarily this is what's called a
droplet virus, so that means that these droplets generally fall to the ground
within three to four feet, so that's why you might be seeing guidance about staying
at least six feet away from each other for example. That's where that comes from is
that's how droplets fall to the ground.
There have been rare reports, probably people that are really sick
who are coughing and sneezing a lot, putting this coronavirus into the air
in what we'd call an airborne manner. That's a lot less common,
but I think possible, so that's why with in especially health care communities
and different facilities that are caring for patients, you see this discussion
about how to best protect patients and families and health care workers between
airborne and droplet precautions. That's where that comes from.