(Reuters) – As the US works overtime to test thousands of people for the novel corona virus, a new blood test offers a way to find out who may have immunity – a potential trailblazer in the fight against infection and to get the economy going again.
FILE PHOTO: Samples from COVID-19 (Coronavirus Disease) tests are logged in the UW Medicine Virology laboratory in Seattle, Washington, USA, on March 18, 2020, for a positive or negative result. REUTERS / Brian Snyder / File Photo
Several academic laboratories and medical companies are rushing to do these blood tests, which can quickly identify antibodies to diseases in people who have already been infected but who may have had mild or no symptoms. This differs from current, sometimes difficult-to-obtain diagnostic tests, which use a nasal swab to confirm an active infection.
“Ultimately, this (antibody test) could help us find out who can normalize the country again,” Florian Krammer, professor of vaccine science at the Icahn School of Medicine on Mount Sinai, told Reuters. “People who are immune could be the first to go back to normal life and get things going again.”
Krammer and his colleagues developed one of the first antibody tests in the United States for COVID-19, the disease caused by the new coronavirus. Krammer said his laboratory was busy distributing key ingredients for the tests to other organizations and sharing the test procedure. He is transferring the work to the Mount Sinai clinical laboratory this week so patient samples can be tested there.
Antibody tests will not face the same bureaucratic hurdles that diagnostic tests originally had. The U.S. Food and Drug Administration relaxed its regulations last month, and body fluid tests can be launched without full review and approval by the agency.
Several private companies have started selling blood tests for COVID-19 antibodies outside the United States, including California-based Biomerica Inc (BOAA.PK) and the South Korean test manufacturer Sugentech Inc (253840.KQ). The test costs less than $ 10, according to Biomerica, and the company already has orders from Europe and the Middle East. New York-based Chembio Diagnostics Inc. CMI.O has announced that Brazil has received a $ 4 million order for its COVID-19 antibody test and plans to investigate the test at multiple sites in the United States.
Such tests are relatively inexpensive and simple, and typically use blood from a fingerprint. Some can produce results in 10 to 15 minutes. This could make starting up the screening much easier than doing diagnostic tests.
According to researchers and experts in infectious diseases, many questions remain, including how long immunity to this new virus lasts, how accurate the tests are, and how the tests are performed. The number of people who have been able to fight the virus is currently unknown.
When the tests are run on a larger scale, some public health experts and clinicians say that healthcare workers and first responders should be given priority.
Recognizing the immunity of doctors, nurses, and other healthcare workers could save them from quarantine and allow them to continue treating the growing number of coronavirus patients. It could also strengthen the ranks of first aiders, police officers and other important employees who are already infected and have at least a certain period of protection against the virus, the experts say.
“If I ever get the virus and then overcome it, I want to get back to the front line as soon as possible,” said Dr. Adams Dudley, pulmonologist and professor at the University of Minnesota School of Medicine. “I would have a time when I am immune, which effectively makes me a” corona blocker “that cannot pass on the disease.”
Other workers who are banned may also be able to return to work and give the declining US economy a much-needed boost. The number of Americans applying for unemployment benefits has risen and business has dropped to a record low this month as the pandemic has hit manufacturing and services.
Dr. William Schaffner, professor of infectious diseases at Vanderbilt University School of Medicine, said companies, schools, colleges, and professional sports teams could all participate in these tests. He also said that a broad sample of tests could give a governor or mayor enough confidence to lift certain restrictions on businesses and schools when there is a high level of immunity.
“These tests would be very attractive if they were inexpensive, readily available, and easy to do,” he said.
Tony Mazzulli, chief microbiologist for the Sinai healthcare system in Toronto, was cautious. It is uncertain whether antibodies would provide adequate protection if a person were exposed to the virus again in very large quantities. This can be done, for example, in an emergency room or in an intensive care unit.
The timing of a return to work and normal life is also important, he said. Some people who have antibodies to the virus may still be contagious, even if their symptoms have eased. Patients start producing antibodies while they are still ill, Mazzulli said, and they shed the virus a few days after they recover.
It would be “somewhat premature” to use the tests to make personnel decisions now, Mazzulli said. “Hope is … (antibodies) provide protection and they can go to work, take the subway, whatever they do. But there is no guarantee. ”
At Mayo Clinic MAYO.UL in Rochester, Minnesota, researchers are preparing for a clinical trial in which patients who tested positive for COVID-19 will have blood drawn at the time of diagnosis and again 15 to 20 days afterwards that in the patient’s house.
The study is intended to show when people with COVID-19 infections “seroconvert” – when antibodies produced by the body appear in blood tests. This information is useful to determine the best time to run the tests.
“They don’t want to do it too early because of the risk of false negative results,” said Elitza Theel, director of the Mayo Serology Laboratory for Infectious Diseases.
Mayo also evaluates the performance of antibody testing from several companies, including two from China.
The U.S. Centers for Disease Control and Prevention said they were working on their own version of antibody tests, but have not given a schedule. The agency has stated that extensive research is underway. A challenge for the CDC and other laboratories is to take enough blood samples from people who are already infected to check the antibody results.
The agency was heavily criticized for sending a faulty diagnostic test to state and local laboratories at the start of the coronavirus epidemic, and then taking weeks to fix it. The federal government is still trying to expand the capacity for diagnostic tests.
Months of immunity
The potential for antibody testing arises as US President Donald Trump is considering reducing “social distancing” and home counseling in the coming weeks. His political allies argue that the burden on the US economy is too high. Approximately half of Americans have been directed to seek shelter because many schools and businesses remain closed indefinitely.
On Tuesday, Trump said: “I would love it if the country opened up and rarely went to Easter.”
However, the reopening of offices and businesses without fear of further infections was hampered by the lack of tests to diagnose COVID-19 cases across much of the country.
On Monday, Dr. Deborah Birx, member of the White House Coronavirus Task Force, that simple fingerprint antibody testing could play an important role, and she suggested that the federal government not wait for the CDC version.
“Some are now developed. We’re looking at those in Singapore, ”said Birx at a press conference at the White House on Monday. “We are very quality-oriented. We don’t want false alarms. ”
False positives are erroneous results, which in this case can lead to the conclusion that someone has immunity if they don’t.
Researchers at the medical school at Duke-National University of Singapore said they quickly developed an antibody test with an accuracy of around 90% and later introduced a more sophisticated version that, according to a report in the Straits Times of Singapore, was more reliable.
Infectious disease experts say that immunity to COVID-19 may persist for several months, and possibly a year or more, based on their studies of other coronaviruses, including severe acute respiratory syndrome (SARS), which occurred in 2003. However, they warn that there is no way to know exactly how long immunity to COVID-19 would last and vary from person to person.
“You probably have immunity for several months,” said Dr. Stanley Perlman, professor of microbiology and immunology at the University of Iowa. “We just don’t know. It’s an incredibly important question.”
Perlman said that many of the new antibody tests currently on the market may be very effective, but researchers want to see data to support this.
“You want them to be sensitive enough to recognize anyone who has had the infection,” Perlman said, “but not so unspecific that you are ingesting other coronaviruses.”
Chad Terhune reported from Los Angeles, Julie Steenhuysen from Chicago and Allison Martell from Toronto; Edited by Julie Marquis