U.S. companies, labs rush to produce blood test for coronavirus immunity
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[March 25, 2020]
By Chad Terhune, Allison Martell and Julie Steenhuysen
(Reuters) - As the United States works
overtime to screen thousands for the novel coronavirus, a new blood test
offers the chance to find out who may have immunity - a potential game
changer in the battle to contain infections and get the economy back on
track.
Several academic laboratories and medical companies are rushing to
produce these blood tests, which can quickly identify disease-fighting
antibodies in people who already have been infected but may have had
mild symptoms or none at all. This is different from the current,
sometimes hard-to-come-by diagnostic tests that draw on a nasal swab to
confirm active infection.
“Ultimately, this (antibody test) might help us figure out who can get
the country back to normal,” Florian Krammer, a professor in vaccinology
at Mount Sinai’s Icahn School of Medicine, told Reuters. “People who are
immune could be the first people to go back to normal life and start
everything up again.”
Krammer and his fellow researchers have developed one of the first
antibody tests in the United States for COVID-19, the disease caused by
the new coronavirus. Krammer said his lab is busy distributing key
ingredients for the tests to other organizations and sharing the testing
procedure. He is transferring the work to Mount Sinai’s clinical lab
this week so it can begin testing patient samples.
Antibody tests won’t face the same bureaucratic hurdles diagnostic
testing initially did. The U.S. Food and Drug Administration relaxed its
rules last month, and body-fluid tests can proceed to market without
full agency review and approval.
Several private companies have begun selling blood tests for COVID-19
antibodies outside the United States, including California-based
Biomerica Inc <BOAA.PK> and South Korean test maker Sugentech Inc
<253840.KQ>. Biomerica said its test sells for less than $10 and the
company already has orders from Europe and the Middle East. Chembio
Diagnostics Inc <CMI.O> of New York said it received a $4 million order
from Brazil for its COVID-19 antibody test, and it plans a study of the
test at several sites in the United States.
Such tests are relatively inexpensive and simple, usually using blood
from a finger prick. Some can produce results in 10 to 15 minutes. That
could make ramping up screening much easier than for diagnostic tests.
Many questions remain, including how long immunity lasts to this new
virus, how accurate the tests are and how testing would roll out,
according to researchers and infectious disease experts. For now, the
number of people who have been able to fight off the virus is unknown.
If testing goes forward on a wider scale, some public health experts and
clinicians say healthcare workers and first responders should take
priority.
Detecting immunity among doctors, nurses and other healthcare workers
could spare them from quarantine and enable them to keep treating the
growing surge of coronavirus patients, they say. It could also bolster
the ranks of first responders, police officers and other essential
workers who have already been infected and have at least some period of
protection from the virus, the experts say.
“If I ever get the virus and then get over it, I'll want to get back to
the front lines ASAP,” said Dr. Adams Dudley, a pulmonologist and
professor at the University of Minnesota School of Medicine. “I would
have a period in which I am immune, effectively making me a ‘corona
blocker’ who couldn’t pass the disease on.”
'VERY ATTRACTIVE'
Other workers sidelined by lockdowns also could potentially return to
their jobs, providing a much-needed boost to the foundering U.S.
economy. The number of Americans filing for unemployment benefits has
soared, and business activity slumped to a record low this month as the
pandemic battered the manufacturing and service sectors.
Dr. William Schaffner, a professor of infectious diseases at the
Vanderbilt University School of Medicine, said companies, schools,
colleges and professional sports teams could all flock to these tests.
He also said a broad sample of testing could give a governor or mayor
enough confidence to lift certain restrictions on businesses and schools
if there is a strong level of immunity.
“These tests would be very attractive if they’re cost effective, readily
available and easy to do,” he said.
Tony Mazzulli, chief microbiologist with Toronto's Sinai Health system,
sounded a note of caution. It is uncertain whether antibodies would be
sufficient protection if a person were to be re-exposed to the virus in
very large amounts. That could happen in an emergency room or
intensive-care unit, for instance.
The timing of a return to work and normal life also matters, he said.
Some people who have antibodies to the virus could still be contagious,
even if their symptoms have eased. Patients begin to make antibodies
while they are still sick, Mazzulli said, and they continue to shed the
virus for a few days after they have recovered.
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Specimens from coronavirus disease (COVID-19) tests are logged to
processed for a positive or negative result at the UW Medicine
Virology lab in Seattle, Washington, U.S., March 18, 2020.
REUTERS/Brian Snyder/File Photo
It would be “a bit premature” to use the tests to make staffing
decisions now, Mazzulli said. “The hope is … (antibodies) do confer
protection and they can go to work, ride the subways, whatever they
do. But there's no guarantee.”
Meantime, at the Mayo Clinic <MAYO.UL> in Rochester, Minnesota,
researchers are preparing to start a clinical trial in which
patients who test positive for COVID-19 would have their blood
collected at the time of diagnosis, and again 15 to 20 days after
that in the patient’s home.
The trial is designed to show when people who have COVID-19
infections “seroconvert” - when antibodies produced by the body
begin to show up in blood tests. That information will be useful in
determining the best time to conduct the tests.
“You don't want to do it too soon because of the risk of false
negatives,” said Elitza Theel, director of Mayo’s Infectious
Diseases Serology Laboratory.
Mayo also is evaluating the performance of antibody tests from
several companies, including two from China.
The U.S. Centers for Disease Control and Prevention said it is
working on its own version of antibody tests, but it has not given a
timetable. The agency has said extensive research is underway. One
challenge for the CDC and other labs is to get enough blood samples
from people who have already been infected to verify the antibody
results.
The agency faced heavy criticism for sending a faulty diagnostic
test to state and local labs early in the coronavirus epidemic and
then taking weeks to fix it. The federal government is still trying
to expand diagnostic testing capacity.
MONTHS OF IMMUNITY
The potential for antibody testing arises as U.S. President Donald
Trump is considering scaling back “social distancing” and
stay-at-home advisories in the weeks ahead. His political allies
argue that the toll on the U.S. economy is too severe. About half of
Americans have been ordered to shelter in place as many schools and
businesses remain shuttered indefinitely.
On Tuesday, Trump said: “I would love to have the country opened up
and just raring to go by Easter.”
Reopening offices and businesses without fear of triggering more
infections, however, has been complicated by the lack of testing to
diagnose COVID-19 cases across much of the country.
On Monday, Dr. Deborah Birx, a member of the White House coronavirus
task force, said simple, finger-prick antibody tests could play an
important role, and she suggested the federal government is not
waiting on the CDC’s version.
“Some are developed now. We are looking at the ones in Singapore,”
Birx said Monday at a White House press briefing. “We are very
quality-oriented. We don’t want false positives.”
False positives are erroneous results that, in this case, could lead
to a conclusion that someone has immunity when he or she does not.
Researchers at the Duke-National University of Singapore Medical
School said they quickly developed one antibody test that had about
90% accuracy and later introduced a more sophisticated version that
was more reliable, according to a report in the Straits Times of
Singapore.
Infectious disease experts say immunity against COVID-19 may last
for several months and perhaps a year or more based on their studies
of other coronaviruses, including Severe Acute Respiratory Syndrome
(SARS), which emerged in 2003. But they caution that there is no way
to know precisely how long immunity would last with COVID-19, and it
may vary person to person.
“You are likely to have immunity for several months,” said Dr.
Stanley Perlman, a professor of microbiology and immunology at the
University of Iowa. “We just don’t know. This is an incredibly
important question.”
Perlman said many of the new antibody tests coming on the market now
may be highly effective, but researchers want to see data to back
that up.
“You want them to be sensitive enough to detect everyone who has had
the infection,” Perlman said, “but not so nonspecific that you are
picking up other coronaviruses.”
(Chad Terhune reported from Los Angeles, Julie Steenhuysen from
Chicago and Allison Martell from Toronto; Editing by Julie Marquis)
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