Do you think you may have had
COVID-19 and didn’t have any symptoms? It’s possible you caught the virus,
known as SARS-CoV-2, and didn’t even know it.
While molecular COVID-19 testing
for those who are experiencing symptoms is now available across the country,
these tests only reveal if someone is currently infected. They do not indicate
if someone has been infected in the past.
However, a new test that measures
the presence of antibodies against the SARS-CoV-2 virus could be a
“game-changer” in our fight against COVID-19. Antibody testing was recently
granted under section IV.D of the U.S. Food and Drug Administration’s (FDA)
Policy for Diagnostic Tests for Coronavirus Disease-2019.
To learn more about COVID-19
antibody testing, we spoke with Banner Health experts, Brian Mochon, Ph.D., a
clinical microbiologist and system medical director of Sonora Quest
Laboratories/Laboratory Sciences of Arizona for infectious disease testing, and
James Utley, system blood bank technical director of Laboratory Sciences of
What is a COVID-19 antibody test?
Antibody testing measures the
development of immunoglobulins, otherwise known as antibodies, which are
produced by your immune system. Your body makes antibodies when it fights off
infections like COVID-19, or when you get a vaccine, such as a flu shot.
Your body makes different types of
antibodies, such as immunoglobulin G (IgG), IgM or IgA. These antibodies,
especially IgG, can last for a long time in your body after the infection has
resolved. Antibody testing, also known as serology testing, can be used to
identify which infections your body has been fighting.
“The COVID-19 antibody test looks
for the presence of the SARS-CoV-2 IgG antibodies that may have developed after
someone has been exposed to or been infected by the virus,” Dr. Mochon said.
“The test may indicate that you’ve been exposed to the virus but have developed
antibodies against it that may protect you from future infection.”
When should I get tested?
IgG antibodies typically develop
between 10-14 days after symptom onset. If you’ve been exposed, diagnosed with
or have recently recovered from COVID-19, speak with your health care provider
on next steps regarding antibody testing.
Where can I get tested?
For some people, antibody testing might not be available yet, but every day cities and states across America are rolling out tests.
If you’ve tested positive for
COVID-19 and have fully recovered (at least 10 days), contact your health care
provider regarding antibody testing.
What if I haven’t tested positive for COVID-19? Can I still get tested?
As with most diagnostic tests, the
performance characteristics of antibody testing were based on samples collected
from patients diagnosed with COVID-19. Because of this, there is limited data
on the effectiveness of this test in individuals who have previously tested
negative for COVID-19 using molecular testing.
Will my insurance cover testing?
Antibody testing prices can vary,
but some laboratories are not billing patients for this test when ordered by a
physician. However, some private labs are offering antibody tests to the
public, with or without a doctor’s referral, for a fee.
How are the results of the test interpreted?
“If an antibody test provides a
positive result for the IgG antibody, it suggests the individual was previously
exposed to SARS-CoV-2, which may indicate a prior infection that has resolved
or is still resolving, and/or protection against re-infection (i.e., protective
immunity),” Dr. Mochon said.
Your health care provider will work
with you to determine the next steps you should take.
Why is the antibody test helpful?
According to a recent white paper
summary issued by the American Clinical Laboratory Association, when used
appropriately, antibody testing may help determine the number of people who’ve
been infected with the virus.
The presences of these antibodies
may aid in contact tracing and general population surveillance to pre-empt
potential future outbreaks and establish “herd immunity” in populations.
“This antibody test is an important
tool in assessing potential risk and fostering a safer environment for all of
us,” Dr. Mochon said. “We look forward to additional science to establish
clearly the role of antibody testing in inferring immunity for COVID-19. Other
respiratory illnesses, including SARS, a cousin to COVID-19, have been shown to
produce antibodies that can be accessed via lab testing to infer immune
protection for a period of time.“
The antibody test may also help
with an experimental treatment called convalescent plasma, a liquid found in
your blood. Convalescent plasma is currently being evaluated as a potential
treatment option for COVID-19 patients in an investigational format with the
“Convalescent plasma is donated from patients who have fully recovered from the virus,” Utley said. “COVID-19 patients produce antibodies located in the plasma directed against the SARS-CoV-2 virus. If you’ve fully recovered from the virus, you can volunteer to donate plasma at your local blood donation center.”