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April 24: OP-ED on OVN OPINION page: Dr. Jim Halverson: 'More information needed on COVID-19 antibody tests'

By Dr. Jim Halverson
It has been five weeks since Gov. Gavin Newsom's Stay At Home Order of March 20. There are still only seven reported cases in the Ojai Valley of COVID-19 and no deaths. On April 18, Ventura County Public Health Officer Dr. Robert Levin slightly eased the previous orders’ restrictions through May 15, as we have seen evidence of flattening of the curve. If we do see a significant increase in cases in Ventura County in the next several weeks, the requirements will again become stricter. Thanks for all of your continued outstanding efforts to follow all of the recommended Public Health guidelines.
With the very recent estimates by University of Southern California and Stanford researchers of as much as a 50- to 80-fold increase in the number of actual people with antibodies to the novel coronavirus, we are receiving calls in the office inquiring about the availability and reliability of antibody testing locally. Here is further information regarding these tests.
How is antibody (serological) testing different from current tests that
are reported daily?
Unlike polymerase chain reaction (PCR) tests — also referred to as molecular tests ­— antibody tests are not intended to identify active SARS-CoV-2 infections. Instead of detecting viral genetic material in throat or nasal swabs, antibody (serological) tests reveal markers of immune response to the infection. The initial IgM and IgG antibodies do not normally appear for at least seven to 10 days after a person begins to feel ill.
Antibody tests are quickly becoming available in two major types.
Rapid disposable serology tests
The market is becoming flooded with commercially available rapid disposable serology tests that resemble home pregnancy tests. The technology is a lateral flow immunoassay performed on a finger-stick blood sample. They are of uncertain reliability and not recommended for individual use since the results — whether positive or negative — are inconclusive. Since the Food and Drug Administration did not require emergency use authorization, many of these disposable tests have not been fully validated. They may be positive from exposure to other common coronaviruses that can cause mild respiratory illness and have been around for many years. Currently, I highly recommend you do not do this test.
ELISA Serology Tests
Enzyme-linked immunosorbent assays (ELISA) tests are performed on a blood-draw sample and run in high-complexity clinical labs. The presence of IgM, IgG or IgA antibodies indicates an immune response to COVID -19. It is not yet known if this immunity will fully protect against future infections.
It is important to select a laboratory that is running a test that has been fully validated by the FDA. There are currently only a small number of labs that are running tests that have full validation. Most laboratories were granted emergency use authorizations to begin running tests that are not yet fully validated. Increasing validation of these tests will happen in the next several weeks.
Ultimately, as these tests become improved and validated, they will be able to identify people who were infected with SARS-CoV-2 and did not know it or were unable to get tested due to an inadequate availability of test kits. Remember, it is estimated that up to a quarter of people with SARS-CoV-2 infection may unwittingly spread the virus because they have mild or no symptoms. Implications for the healthcare workforce and our country's return to less social distancing will be dependent upon verifying current immunity levels in our population and identifying people who can safely work with COVID-19 patients in the future.
I am currently advising my patients to wait for at least several more weeks before doing an ELISA antibody test until we more fully understand if positive antibodies give adequate immunity to protect against future infection and contagiousness to others. Responsible leadership, including our state's COVID-19 task force, will be issuing updated guidelines as further data is collected.
Patience is so difficult in this time. People are out of work, struggling with anxiety about the potential severity of this infection and suffering from lack of in person human contact. I salute all of you as we all move forward to establishing safe ways to be able to once again fully enjoy this beautiful valley that we call home.
Until that time comes, stay home, stay safe and stay well.

 

— Dr. Jim Halverson is a longtime Ojai physician who is providing weekly updates to the Ojai Valley News on COVID-19.

 

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