On April 6, the U.S. Food and Drug Administration (FDA) announced it has issued an emergency use authorization (EUA) for the Symbiotica COVID-19 Self-Collected Antibody Test System, the first antibody test authorized for use with home collected dried blood spot samples. Samples collected at home are then sent to a Symbiotica, Inc. laboratory for analysis.
“The authorization of the first prescription use, home collection antibody test will play an important role in helping health care professionals identify individuals who have developed an adaptive immune response from a recent or prior COVID-19 infection,” said Jeff Shuren, M.D., J.D., director of the FDA’s Center for Devices and Radiological Health. “The FDA will continue to authorize COVID-19 tests that will give more Americans access to greater testing flexibility and options.”
The COVID-19 Antibody Test
Antibody or serology tests look for antibodies in your blood to determine if you had a past infection with the virus that causes COVID-19.
- Antibodies are proteins created by your body’s immune system soon after you have been infected or vaccinated.
- Antibodies help you fight off infections and can protect you from getting that disease again. How long this protection may last is different for each disease and each person.
Antibody tests should not be used to diagnose a current infection with the virus that causes COVID-19, except in instances in which viral testing is delayed. An antibody test may not show if you have a current infection because it can take 1–3 weeks after the infection for your body to make antibodies.
There are two key measures of an antibody test’s quality: its sensitivity and specificity. Highly sensitive tests can accurately detect whether people have antibodies present in their blood. If a test is described as highly specific, this means that it’s specific to a particular type of antibody and can also reliably detect people who do not have covid-19 antibodies. The presence of some types of antibodies can give an indication of when a person may have been infected.
So far, the quality of antibody tests for covid-19 vary in quality, but several offer sensitivity and specificity near to or even at 100%, say their manufacturers. Very occasionally, an antibody test may give a false positive result (suggesting that people have covid-19 antibodies when in fact they do not) because of cross reactivity with coronaviruses other than SARS-CoV-2, for example. Need to remember, there no test can always be 100% accurate.
Symbiotica Self-Collected Antibody Test System
The COVID-19 Self-Collected Antibody Test Systemv is authorized for prescription use with a fingerstick dried blood sample that is self-collected by an individual age 18 years or older or collected by an adult from an individual 5 years of age and older. The test is intended to aid in identifying individuals with an adaptive immune response to SARS-CoV-2, indicating recent or prior infection. The COVID-19 Self-Collected Antibody Test System should not be used to diagnose or exclude acute SARS-CoV-2 infection. At this time, it is unknown how long antibodies persist following infection and if the presence of antibodies confers protective immunity.
Antibody tests, also known as serology tests, detect antibodies present in the blood when the body is responding to a specific infection, as with SARS-CoV-2. COVID-19 antibody tests can help identify people who may have had a prior infection or who may have recovered from COVID-19. However, these tests cannot detect the presence of the SARS-CoV-2 virus to diagnose COVID-19.