- [Daniela] With a vaccine against the new coronavirus
many months, if not years, away,
scientists and doctors are racing
to treat the disease it causes.
They have identified antibody testing
and blood plasma therapeutics as promising approaches
to mitigating the health and economic-related fallout
from the pandemic.
These technologies could also help us learn more
about how widely the virus has spread.
- It's based on the same principle
of, if you have a protective antibody,
passive transfer of that could provide
not only protection prophylactically, but also treatment.
- When patients recover from a viral infection,
they produce virus-fighting proteins known as antibodies.
These circulate in a person's blood
and help protect against future infections.
Antibodies are particular
to the invader they're produced to fight off.
If they're found in the blood,
that means the person was infected
and that they now have the molecular defenses
to fight that virus off, a process known as immunity.
In theory, doctors could transfer these antibodies
to a person who is still sick
so these proteins could help them recover.
This kind of therapy has been tried in the past
during previous public health crises.
- It was used in the 1918 flu epidemic.
It was used in many outbreaks of mumps, polio,
and measles in the early 20th century,
and it continues to be used
as recently as the SARS epidemic of 2003.
- [Daniela] The treatment,
known as convalescent plasma therapy,
is gaining traction now because there aren't other
approved alternatives for treating COVID-19.
- The word stopgap is often associated with it,
and the reasons is it is available today.
- [Daniela] The safety and efficacy
haven't been established yet through clinical trials,
which is the gold standard,
but preliminary tests in China
have shown encouraging results, and in March,
the FDA started to allow doctors in the U.S.
to treat some patients with the plasma
of those who have recovered from COVID-19.
- For the recipients, we're looking for people
who are admitted to a hospital
who are showing increasing oxygen requirements,
which indicate to us that they're on
potentially a downhill course.
- Mount Sinai in New York
is one of a growing number of hospitals across the country
administering convalescent plasma
to qualifying COVID-19 patients.
Recovered patients interested in donating plasma
fill out a survey.
Then, to comply with FDA guidelines,
clinicians have to put these potential donors
through two tests, first, a diagnostic test.
They have to make sure they're not still carrying
the new coronavirus, and then an antibody test
to ensure they're making enough antibodies
to fight the virus off.
That second test looks for antibodies in blood plasma.
Scientists at Mount Sinai developed an antibody test
by starting with the genetic code for the virus.
That serves as the blueprint for proteins.
Using these instructions,
they mass-produce synthetic copies of a protein
that the virus has on its surface.
Then they take special plates with dozens of tiny wells
and coat the bottom of each one with the synthetic proteins.
After that, they put some of the donor plasma
into each well.
If there are antibodies,
these recognize the viral protein and bind to it.
The scientists then add an additional antibody
which lights up when it binds to the synthetic viral protein
and coronavirus antibody combo.
Scientists run this test at different concentrations
until it stops lighting up.
The more they have to do the sample,
the more antibodies the person's plasma has.
The more antibodies, the better the plasma is for therapy.
Scientists do this kind of testing in labs all the time,
but to do it clinically, they need to notify regulators.
If a potential donor passes the virus
and the antibody tests, then Mount Sinai clinicians
ask them to go to the New York Blood Center
where they can give enough plasma
to administer to patients.
Then there are two other hurdles
before that plasma can be given to patients,
making sure it doesn't have any other viruses
like hepatitis or HIV, and the blood types have to match.
One donation can likely treat two people
according to preliminary estimates.
So far, Mount Sinai has treated more than 30 patients.
Administering the therapy requires sign-off from the FDA.
How will you tell if somebody's getting better
because of this treatment?
- Well, in about four or five days,
hopefully they'll be recovering more quickly
than other people with similar characteristics.
We have a team of bio statisticians that are starting
to model what happens for patients in our experience
in the health system, such as the length of hospital stay,
the need for ICU days, the need for a ventilator,
and of course, mortality and survival
are, of course, the ultimate.
- The treatment is not without risks.
Transfusion reactions can include fever, allergic reactions,
and even lung injury, and like the swab tests
that tell somebody if they have the virus,
antibody tests are also in short supply.
In the long-term, the hope is that they could help mitigate
some of the economic effects of the pandemic.
So right now, I'm talking to you from my apartment.
You're in your house in Baltimore, I imagine.
Could this kind of testing also help policy makers
figure out who is able to go back to work safely?
- If we knew who has antibody and they have recovered,
you could imagine that those could go work safely.
It would require an enormous undertaking
to test almost everyone in the country.
- [Daniela] The antibody tests
also have to be highly accurate, and recently,
the accuracy of some tests developed abroad
has been called into question.
Despite the challenges, scientists are optimistic
that plasma therapy could help patients recover faster
and give them clues about how deadly the virus really is.
- We don't know the denominator.
We don't know the number of people
that have been infected but did not have disease,
and the presence of antibody in their blood
will identify that subset, and you need to know that number
to know really how lethal this disease is.
(pleasant bell music)