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.