As the novel coronavirus spread around the globe, the World Health Organization called
on countries to act quickly. “We have a simple message for all countries: test, test,
test.” Testing is information. When you have testing, then you can know who
is infected, who need to take special care to keep isolated, it’s the power of that
information. There's been a range of responses depending on where you are in the world, with
countries racing to identify as many cases as possible to slow the spread of this pandemic.
There are two important tests - one that can confirm if you’re currently infected, another
that can tell if you’re immune. And both are important for our collective recovery.
After pneumonia cases started to rise in Wuhan, researchers in China worked quickly to isolate
this new coronavirus, sequence it, and publish its genome. Shortly after, a team in German
designed the world’s first covid-19 diagnostic test. “This is a polymerase chain reaction
test, nothing special, standard procedure in labs. The special thing about this is that
there's an essential ingredient, a molecule, that we provide. So we just ship this via
a postal envelope to laboratories wanting to establish this test.” A polymerase chain
reaction test, or PCR, is a standard molecular biology technique that scientists have been
using for decades. HIV would be one of the very first diseases where it left the research
lab and became widely used so scientists could figure out what the genetics are of different
viruses. My lab is a T-cell lab. The tools that we use to look at T-cell responses against
HIV are completely applicable to studying any virus. My friends, colleagues around the
country are also virologists or immunologists. Many of them also have immediately made the
shift over to COVID-19. It's plug and play. That infrastructure is there. To find out
if you have this virus, a doctor will give you a RT-PCR test, or a reverse transcriptase polymerase chain reaction. It’s a molecular photocopying
technique that can detect the presence of a virus’s genetic material in a sample.
To understand how that works, let’s take a closer look at this coronavirus. It has
a protein shell and these characteristic spikes. Inside the shell is it’s genome - a single
RNA strand instead of a double helix. It’s like the virus’s instruction manual that
it uses to take over a human cell. A RT-PCR test uses chemicals and a special enzyme to
convert that RNA into DNA, and then make billions of copies quickly confirm if there’s an
infection. And it all starts with an awkward swab. All of the current tests involve a nasopharyngeal
swab. So that is a very long swab that's inserted through the nose and is pushed all the way
back to the sinuses. [videos of TikTok swabs] It looks horrible, yeah. You really want to
get back there to the areas where the virus is replicating. It replicates on respiratory
mucosal surfaces...It likes the back and all the way down into the lungs. Then all of the
mucus and cells from that swab are then lysed in a detergent, so they're broken up. And
then the RNA that's in there is extracted. The RNA is turned into DNA with an enzyme
called reverse transcriptase. And that's because the PCR test requires DNA. It can't be run
directly in RNA. And then once we have that DNA made from what's in the swab, PCR, basically,
is done by adding other bits of DNA that would bind to viral DNA. And then there's what's
called a chain reaction, polymerase chain reaction where more copies are made if they
are present. If the viral DNA is there, the PCR reaction will then amplify the viral DNA
there, then it's a positive test.The World Health Organization published the German team’s
PCR test protocols and distributed over 1 million tests worldwide. South Korea, Singapore,
Germany and other countries responded quickly and deployed hundreds of thousands of diagnostic
tests. Here in the United States. Unfortunately our CDC did not even take kits that the WHO
was providing, but decided they wanted to do it themselves, which is fine. But it's
fine if they do it properly. If you look in the news reports, their kits were defective.
They were far too few in volume, and so nobody had any test kits. And in the meantime, policies
prevented others from developing tests. We have a very large infrastructure of private
companies and university labs that all can do this. It is not complicated. It's not difficult.
The CDC now has loosened up and is allowing individual labs to now get testing going in-house
with their own protocols, but promise those protocols have to follow exactly the CDC version.
This PCR test is important for detecting current infections, but only for a specific window
of time. Because when you recover, your immune system is clearing the virus. If somebody
had a mild case and they recover, we have no way of knowing whether it was COVID-19
or not. But if we have an antibody test, we can actually find those people.
It’s also called a serological test, and it looks for the presence of antibodies in
a blood sample. This would help experts track the full scale and spread of the virus, and
confirm who is currently immune. Antibodies play a very important role in the
immunity against a lot of viruses. They can basically kill the virus by either interfering
with its ability to infect the cell because it's physically blocking, or they can actually
tag the virus and activate the immune system so that other cells come in and see that tag,
and attack. We harness that because we have good technologies … to figure out whether
somebody has antibodies. The antibody test uses a diagnostic technique called an ELISA,
enzyme linked immunosorbent assay. Inside the wells in this plate are tiny pieces of
the virus. When a patient’s blood is added, any coronavirus-fighting antibodies present
will bind to those pieces. Specialized enzymes and substrates are then added which change
the color of the well if bound antibodies are present. Antibody tests are currently
being used in Singapore and China, with other countries racing behind them to bring their
own online and rolling out immunity certificates. This is an important test that could find
asymptomatic carriers, clarify who’s safe to work on the frontlines , help with future
treatments, and could be a key indicator for when we can re-enter society.
But this test is not a quick fix. We don’t know yet if testing positive for antibodies
means a patient is fully immune to the virus. Researchers are moving fast here, but there’s
only been so much time. The harder part is finding blood from people
who have had coronavirus, who have recovered. Because antibodies are made in the course
of the disease, and so if you're actually acutely ill, you probably won't have antibodies
yet. We are looking for people that have recovered. Anyone out there that's interested, please
contact me. All of this is in the works, and it's going through much more quickly than
usual because everybody does feel a sense of urgency. So people have really been kind
of heroic in stepping up. I think those of us that have been around for a while, it's
a bit reminiscent of the AIDS epidemic. It's got a lot of the same flavor where people
are confused, there's a lot of misinformation, people are trying drastic things. But what
I hope is that out of it will come really good useful treatments or vaccines, just like
HIV treatments came relatively quickly and amazingly effectively.