How Does COVID-19 Spread?

The ease in which a virus spreads can vary. COVID-19 seemingly spreads more efficiently than the flu,
but appears to be more ineffective than the spreading of measles. Even though there is still much we
need to discover about how COVID-19 spreads, we do know that the best way to prevent against
infection of the coronavirus is by avoiding exposure.
So far we know that COVID-19 seems to spread most easily from person to person when in close
contact. The virus can be spread in this manner by infected individuals with or without symptoms of
COVID-19. According to the CDC, the greatest risk of coronavirus infection occurs when someone has
been in direct contact up to a distance of six feet of an infected person. Additionally, as the amount of
time spent with an infected person increases, so does the risk of infection.
When people cough, sneeze, talk, sing and even when they breathe, they produce respiratory droplets.
Respiratory droplets can cause infection when they are inhaled or land on mucous membranes, such as
those in the nose, mouth and eyes.
These droplets can range in size from larger droplets that can be visible, to smaller droplets that can
remain airborne. Airborne transmission is the primary method of infection for sicknesses such as
tuberculosis, measles and chicken pox.
The larger droplets fall out of the air due to gravity. The farther the larger droplets travel, the more their
concentration decreases, most falling to rest around the infected individual; and the more time passes,
the more the amount of infectious virus within these respiratory droplets – large or small – decreases.
The smaller virus-filled particles that remain in the air, floating and following the air streams, beg further
research. We still need to know how much this mode of transmission contributes to the spread of
COVID-19. More specifically, how common it is, the ease in which it travels, the length of time it lingers,
What we do know is that these small droplets that can spread infection through exposure can linger in
the air from between minutes to hours; and they can spread to people after an infected person has left
a space – such as in the instance of someone entering an elevator after an infected person has already
exited it.
We also know that small, airborne droplets lingering in the air can infect people who are further than six
feet away – such as in the instance someone jogs behind an infected jogger in the park. Although this
type of transmission is a higher risk within enclosed spaces and worse when those spaces have poor
ventilation and they are crowded with more people who could possibly be infected with COVID-19.
It is, however, according to the data that is currently available, much more common for COVID-19 to
spread via close contact than through the airborne transmission just mentioned.

Less common than the person to person spread of COVID-19 is the spreading of coronavirus through
contact with contaminated surfaces. How this works is that when virus-filled respiratory droplets land
on surfaces, people touch those surfaces and then touch their own mouth, nose or eyes.
This means that the things we touch on a daily basis, such as our cellphones, keyboards, countertops,
remote controls, light switches and more can host coronavirus-filled droplets for a few minutes to
several days. The survivability of the virus can vary from surface to surface. The particular length of time
is dependent upon the material of that surface.
For example, according to some sources, metals such as doorknobs can host the virus for up to five days.
The virus can last on wood including tables, decking and wooden railings for four days. While it’s
probably about two to three days for plastics such as milk containers and other plastic cartons
containing grocery items, as well as detergent bottles, subway and bus seats, backpacks, elevator
buttons and cigarette packs. The cardboard we use for take-out pizza and shipping boxes can infect us
for us to 24 hours. Glass, such as drinking glasses, windows and mirrors can house the virus for up to five
days. Ceramics like some of our toilets, dishes and sinks are at about five hours. COVID-19 can also
spread through paper items, such as our mail, newspapers and lottery tickets, anywhere from minutes
to five days. The virus can even last on copper pennies for four hours.
As COVID-19 can spread from person to person and from surface to person, it also appears that COVID-
19 can spread from people to animals in certain situations. Although this type of infection is not as
common, there are a small number of recorded cases of pets, including cats and dogs, as well as zoo
animals that have contracted coronavirus from COVID-19 infected people with whom they shared close
There are still massive amount of data we need to collect and so much we need to learn about the how
COVID-19 spreads. Riverside Clinical Research, an award-winning facility with a well-earned reputation
for trendsetting in clinical trials, is dedicated to the research surrounding coronavirus.
The medical and research professionals at Riverside Clinical Research are currently planning clinical trials
for COVID-19. If you are interested in helping to combat COVID-19 by becoming a clinical research
volunteer, simply call Riverside Clinical Research for more information at 386-428-7730 Monday through
Thursday from 7 a.m. to 5 p.m. or Friday from 7 a.m. to 12 p.m. If you have any questions, you can also
email those to Additionally, feel free to learn more about the
clinical research trials at Riverside Clinical Research by accessing our patient portal which can be found
on our website. Riverside Clinical Research is conveniently located at 1410 S. Ridgewood Avenue in