It’s hard to write about the science
of COVID-19 right now because our understanding of the virus is still
evolving. But it’s also hard to think about anything else.
One thing everyone wants to know is how
and when this pandemic will end. In the best-case scenario, a vaccine
becomes available and life goes on as normal. The problem is that it
will take at least a year – even with international cooperation,
dedication and determination – to develop, test, and then
distribute the vaccine worldwide.
To find out more about viruses and vaccines,
click on this link to read Virus VS Bacteria – Know Your Enemy on
Sci/Why, written by our own Adrienne Montgomerie.
In the meantime, everyone will have to
stay at home unless we can find a way to quickly and accurately
identity who has the virus and who doesn’t. Unfortunately, testing
for COVID-19 has been difficult.
There are two main steps to testing a
person to see if they’ve been infected with COVID-19.
Step One: Collect the Sample
The sample must be collected by someone
wearing a mask that can protect them from getting infected. It’s
done with a nasopharyngeal swab, which is basically a long cotton
swab that goes into the nose.
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| Photo by cottonbro from Pexels |
Step Two: Test the Sample
Getting enough lab space to do the
testing has been difficult as well, since the lab has to be specially
designed so the virus won’t spread. The test itself requires
specific chemicals and machines, which have also been in short
supply.
To find out whether there’s any
COVID-19 virus in the sample, scientists look for its RNA. Like DNA
in humans, RNA is a set of instructions that makes each type of virus
unique. To cause an infection, the COVID-19 virus injects this
genetic material into a human cell (it really likes lung cells) along
with instructions on how to make copies of it. This allows the RNA to
be copied over and over again until the cell dies. Then all those
copies of RNA are released in the form of new COVID-19 viruses that
can attack other cells.
To find out more, click on this link to watch The
Coronavirus Explained & What You Should Do
on Kurzgesagt – In a Nutshell.
If someone has the COVID-19 virus,
there will be pieces of its RNA in the sample collected during step
one. The most common way to test a sample for viral RNA is by
something called polymerase chain reaction (PCR). It sounds
complicated but PCR is really just way of making more RNA using the
virus’s genetic material as a template – not that different to
what the virus does itself when it causes an infection. If the virus
is in the sample, PCR will produce enough RNA to been seen using a
special microscope.
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| Artist's image of DNA, from the National Institute of Health |
Scientists all over the world are
trying to find different ways of making step two faster and more
efficient. One way is to use CRISPR, a gene editing tool that works
like the find and replace function in a word document to change DNA
in ways that have never been possible before. With cool names like
SHERLOCK and DETECTR, these tests could get results in as little as 5
to 10 minutes by a process that may eventually be used to not only
detect the virus but destroy its genetic material as well.
My book, CRISPR: A Powerful Way to
Change DNA, comes out this fall from Annick Press. It will go to press before we know
how much CRISPR will be used in the fight against COVID-19.
It’s
exciting to think about how new technologies might stop future
viruses through testing, treating and even developing vaccines. But
the current pandemic is teaching us that the supply of basic stuff -
masks, swabs, lab space and equipment – is really the most
important thing of all.
