Authorities and health workers have been using Serologic tests (looking for antibodies in the blood) to differentiate between infected and non-infected Coronavirus patients.
The antibody test checks the presence of antibodies formed in response to the body’s immune response against the Coronavirus infection.
Coronavirus News: CDC Explains Why Antibody Tests Are Inaccurate
In an official statement, CDC said, “Antibodies in some people can be detected within the first week of illness onset.” However, the tests are not accurate enough, and therefore authorities making real-world decisions based on this can be problematic.
The CDC warned that antibody tests “should not be used to make decisions about grouping persons residing in or being admitted to congregate settings, such as schools, dormitories, or correctional facilities.”
Furthermore, these tests should not be used “to make decisions about returning persons to the workplace.”
The US CDC recommended that doctors and other health care workers use the most accurate antibody tests available to declare a person infectious or non-infectious. Additionally, the CDC also directed the authorities to test people twice to receive the most accurate readings.
The CDC explains that Coronavirus, specifically SARS CoV-2, antibodies in most patients around the world “are expected to be low, ranging from less than 5% to 25%, so that testing at this point might result in relatively more false-positive results and fewer false-negative results.”
A false-positive result could declare an infected person non-infectious or vice versa.
Even with the most “truly positive antibody test results,” CDC says we cannot assume that the person will remain protected from future infections.
The COVID-19 antibodies cannot be touted to grant immune status to users until researchers don’t prove the “presence, durability, and duration of immunity.”
In order to avoid false positives, the CDC suggested the use of antibody tests with high specificity. Such a test allows for the accurate detection of the target protein while ignoring the rest of the similar bunch. Such tests should be used only in an area where a large infected population is suspected to reside.
Presently, all those who are battling COVID-19 should be given a viral test instead of an antibody test to identify virus samples in patients’ respiratory systems.