By Dr. William E. Kim, MD, Chief Medical Advisor, Beach Cities Health District

News of COVID-19 serology tests coming to market have created confusion in the general public. Many are wondering what the difference is compared to tests being administered at testing sites around Los Angeles County and whether these tests can diagnose whether a person has COVID-19. With increasing COVID-19 scams and false marketing, it’s important to know the facts.

Serology testing, also known as antibody testing, is a serum or blood test for IgM and IgG antibodies to COVID-19. If the test is positive for IgM antibodies, then there is an acute or active infection, meaning the individual has the infection. The IgM antibodies diminish over weeks. IgG antibodies are produced as the IgM antibodies start to diminish and can persist for an extended period of time. In other words, if the antibody test shows IgM antibodies present, the individual is likely in the early stage of infection, if both IgM and IgG antibodies are present, they are in the middle stage, and if only IgG antibodies are present, then they are either in the last stage or over the infection. Antibody tests can show if an individual has or had the infection, whether symptomatic or not; they detect the body’s immune response caused by COVID-19, rather than detecting COVID-19 itself.

Because antibodies may not be detected in the early days of infection, antibody testing is not effective for diagnosing COVID-19. This means a negative result on an antibody test does not rule out infection. Some antibody tests are being falsely marketed as “FDA authorized” or “FDA approved.” No antibody tests are currently approved for use in the point of care setting by the FDA. Status of FDA approval changes daily.

With new antibody tests coming to market that are not FDA approved, companies have been falsely claiming that their tests can diagnose COVID-19. There are no validated antibody tests, at-home test kits or vaccines for COVID-19. Today, the only appropriate tests for diagnosing COVID-19 are molecular tests available through your health care provider or at testing sites through the L.A. County Department of Public Health, like the testing site at the South Bay Galleria in Redondo Beach. Beach Cities Health District has been working with L.A. County, the city of Redondo Beach and Providence Little Company of Mary to support COVID-19 testing efforts at the South Bay Galleria. Testing at the South Bay Galleria has ramped up to 400 appointments a day with more than 3,600 tests completed. Visit corona-virus.la/testing to determine eligibility and schedule a COVID-19 test at a testing site in L.A. County.

Here’s how to protect yourself from COVID-19 scams:

• Watch for texts and emails claiming to be from the World Health Organization or CDC, “experts” saying they have information on or treatments for the virus, or alerts telling you to self-isolate or get tested for the virus
• Do not respond to these texts and emails
• Do not click on any unknown links in these texts or emails
• Hang up on robocalls and do not press any numbers

Although antibody testing is not used to diagnose COVID-19, its purpose is essential. This type of surveillance data helps us better understand how prevalent or widespread COVID-19 is in our community, especially among individuals who have been infected and show no symptoms and, in the future, can inform strategies for recovery. Early results from the USC-L.A. County seroprevalence study estimate that 4.1% of L.A. County’s adult population has antibody to the virus. The statistical margin of error suggests that 2.8-5.6% or 221,000-442,000 adults in the County have had the infection. This estimate is 28-55 times higher than the number of confirmed cases. Early results from antibody testing show that COVID-19 is much more widespread across the County than previously thought.

If you’ve recovered from COVID-19, you may have antibodies in your plasma that attack the virus. Please consider donating plasma to help those in need. Visit UCLA Health or the American Red Cross for more information. 

Board certified in internal medicine, Dr. William E. Kim, MD, specialized in emergency medicine for 10 years at the old South Bay Hospital, then transitioned into private practice with the South Bay Family Medical Group. Today, Dr. Kim manages his own practice, which provides personalized 24/7 services, and serves as Chief Medical Advisor for Beach Cities Health District.

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