COVID-19 / VIRUS Bloomberg Businessweek March 16, 202058
COURTESY JACKSON LABORATORYWhat I’m
telling
everyone
David Ho, M.D., world-
renowned pioneer in
HIV research. Scientific
director of the Aaron
Diamond AIDS
Research Center and
professor of medicine
at Columbia University
Irving Medical Center,
New York
I say act sensibly.
An infected person
should stay home. If
you’re coughing or
sneezing, wear a mask
to contain the virus
as much as possible.
I usually advise a mask
for a sick person and
a health worker who
has to be face-to-face
with a sick person.
I don’t recommend
wearing masks as the
Chinese wear them,
everywhere on the
street. To a large extent
that’s useless, and most
aren’t appropriate.
If you use an N95
mask, it’s suffocating.
It’s extremely
uncomfortable.
I emphasize hand
hygiene. We know
from flu and SARS that
most of the infection is
acquired from touching
contaminated surfaces
and bringing the virus
to your mouth or eyes.
That’s the major route.
Here in my lab, we
try to disinfect the
common areas—
doorknobs, handrails,
elevator buttons—on
a frequent basis.
Everyone should be
on alert about hand
hygiene and cleaning.
—As told to Susan
Berfield and Robert
Langreth○ The new coronavirus causes little more than
a cough if it stays in the nose and throat, which it
does for the majority of people unlucky enough to
be infected. Danger starts when it reaches the lungs.
One in seven patients develops difficulty
breathing and other severe complications, and
6% become critical. These patients typically suffer
failure of the respiratory and other vital systems,
and sometimes develop septic shock, accord-
ing to a report by February’s joint World Health
Organization-China mission.
The progression from mild or moderate to severe
can occur “very, very quickly,” says Bruce Aylward,
a WHO assistant director general who co-led a
mission in China that reviewed data from 56,000
cases. Understanding the course of the disease andidentifying individuals at greatest risk are critical
for optimizing care. About 10% to 15% of mild-to-
moderate patients progress to severe, and of those,
15% to 20% progress to critical. Patients at highest
risk include people age 60 and older and those with
preexisting conditions such as hypertension, diabe-
tes, and cardiovascular disease. “The clinical picture
suggests a pattern of disease that’s not dissimi-
lar to what we might see in influenza,” says Jeffery
Taubenberger, who studied the infection in victims
of Spanish flu, including one exhumed more than 20
years ago from permafrost in northwestern Alaska.
Covid-19 most likely spreads via contact with
virus-laden droplets expelled from an infected
person’s cough, sneeze, or breath. Infection
generally starts in the nose. Once inside the
body, the coronavirus invades the epithelial cells
that line and protect the respiratory tract, says
Taubenberger, who heads the viral pathogenesis
and evolution section of the National Institute
of Allergy and Infectious Diseases in Bethesda,
Md. If it’s contained in the upper airway, it
usually results in a less severe illness. But if the
virus treks down the windpipe to the peripheral
branches of the respiratory tree and lung tissue,
it can trigger a more serious phase of the disease.
That happens because the virus directly inflicts
pneumonia-causing effects, and the body’s immune
response to the infection causes secondary harm.
“Your body is immediately trying to repair the
damage in the lung as soon as it’s happening,”
Taubenberger says. Various white blood cells that
consume pathogens and help heal damaged tis-
sue act as first responders. “Normally, if this goes
well,” he says, “you can clear up your infection in
just a few days.”○ When does the body fight itself?
In some more severe coronavirus infections, the
body’s effort to heal itself may be too robust, lead-
ing to the destruction of not only virus- infected
cells but also healthy tissue, Taubenberger says.
Damage to the epithelium lining the trachea
and bronchi can result in the loss of protective
mucus-producing cells as well as the tiny hairs, or
cilia, that sweep dirt and respiratory secretions out
of the lungs. “You have no ability to keep stuff out
of the lower respiratory tract,” Taubenberger says.
As a result the lungs are vulnerable to an invasive
secondary bacterial infection. Potential culprits
include the germs normally harbored in the nose
and throat, and the antibiotic-resistant bacteria
that thrive in hospitals, especially the moist envi-
ronments of mechanical ventilators.hy do
ome people
et so sick?
take their own samples for drop-off at a doctor’s
office, says Lothar Wieler, head of the institute.
“There will need to be more such solutions,” Wieler
told reporters on March 9 in Berlin. “Otherwise,
we won’t be able to handle the number of patients
needing tests.”
With demand surging, Landt is trying to rent
space in a building across the street to expand pack-
aging and mailing—the bottleneck of his operation.
He’s hired a team of students who sit at a long table
packing the kits in flat plastic bags, and he bought
a used machine that folds instruction manuals to
fit in the bags. His 21-year-old son, Aaron—a math
student—oversees labeling. (“It’s a 60-hour-a-week
part-time job,” Landt says.) His wife, Constanze,
a biology Ph.D. in charge of TIB’s procurement,
anticipated the demand surge more than a month
ago and laid in extra supplies of the basic chemi-
cals for the tests. Without that, “nothing would be
working anymore,” Landt says, but those stocks are
running low. The next challenge, he predicts, will
be keeping up with likely mutations of the virus,
which would render his tests less reliable. “A virus
like this is a major evolution machine,” he says
before hustling back to his office. “We can calm
down when there’s a vaccine.” —Stefan Nicola,
with Tim Loh and Heejin Kim