What is Antibody (Serology) Testing?
An antibody or serology test is a blood test that looks for signs of a previous COVID-19 infection. It detects antibodies, which are proteins in the blood that fight-off infection. Antibody testing has a lot of promise because it will help us understand the pervasiveness of COVID-19 in our communities.
But, antibody testing shouldn’t be relied on for accurately predicting individual immunity. This means that even if you receive a positive antibody result, showing that COVID-19 antibodies were detected, you will not know with any certainty that you cannot get COVID-19 again. Everyone should continue to follow the recommendations on physical distancing and hygiene until scientists and doctors understand the disease better.
COVID-19 quick links:
- UCLA Health clinical trials
- Convalescent Serum Project
- Stop COVID-19 Together data project
- COVID-19 FAQs
- Sign-up for health news & information
Patient hotline 310-267-3300, Mon to Fri, 7 am to 7 pm
What is the difference between antibody testing and diagnostic testing?
An antibody test is a blood test that looks for signs of a previous COVID-19 infection.
A diagnostic test looks for signs of an active, current infection. The preferred diagnostic test is still a nasopharyngeal (through the nose) swab. This test can be performed at one of UCLA Health’s almost 30 test locations and sent to an UCLA in-house lab for testing.
How does an antibody test work?
A blood sample collected in a vial is sent to a lab where a test is run to look for the presence of antibodies in the blood serum. The presence of antibodies means that the body had an immune response to fight off a virus.
The common test that is used for serologic testing is called the ELISA test, for enzyme-linked immunosorbent assay. Right now, antibody tests for COVID-19 return many false positive results. This means that even if the test returns a positive result, implying that someone has COVID-19 antibodies and already recovered from the coronavirus disease, that might not be the case.
Does UCLA Health offer antibody testing? Who can get tested?
Yes, UCLA Health has an antibody test available, but it must be ordered by a primary care physician. If you need to establish care with a primary care physician, we can help. Please call 310-825-2631 for a referral to one of our many primary care clinics across the region.
Antibody tests are recommended in the following cases:
- As part of a clinical trial for health system workers and first responders
- In combination with diagnostic testing for patients who are scheduled for a procedure or surgery
- In the setting of a potential plasma donation with prior diagnosed or suspected COVID-19
- In cases when a patient had a suspected COVID-19 infection, but no testing was performed
- In cases when a patient had a suspected COVID-19 infection, but despite a negative diagnostic test result, their physician still thinks they had the disease and wants to confirm
- In other cases, approved by a physician, such as when someone is in close contact with high-risk patients (immunocompromised or elderly) and may have been exposed to the virus in the past
The test is currently NOT offered:
- To diagnose active COVID-19
- For low-risk patients or members of the general public with no suspicion of recent infection who may simply be curious or want to know if they were infected
How long does it take to get results from an antibody test?
The expected turnaround time is 24 to 48 hours.
If my antibody test is positive and I have COVID-19 antibodies, am I immune?
The quickest answer is, we don’t know.
Right now, scientists do not fully understand how the presence of antibodies relates to immunity. They do not know if someone can be re-infected with COVID-19 if they already had the disease, or for how long potential immunity might last.
As more research on coronavirus and COVID-19 is conducted and the immune response to the disease is better understood, scientists and doctors will better understand the relationship between antibodies and immunity.
I think I may have been exposed to COVID-19. Can I get the test?
You should talk to your primary care physician about your concerns and let them know if you believe you were exposed to COVID-19. They will decide if an antibody test is appropriate given your specific case.
Please note that you must be asymptomatic at the time of the COVID-19 antibody test. In order to maximize the likelihood of accurate results, the test should be ordered at least 28 days after the onset of symptoms.
You can call your physician’s office or 310-825-2631 to set up a video visit or in-person appointment to discuss antibody testing.
What does it cost?
Patients should check with their individual insurance plans. Patients may have to pay a deductible, so even if the test is covered, they may need to pay for the cost of the test.
What do I need to know?
The most important thing for patients to know is that while antibody tests can provide important information to researchers and groups making public health policies, they are not yet useful to the general public as a means of confirming a prior COVID-19 infection or providing information about immunity.
Because these tests are not perfect, it is important to continue to follow evidence-based steps regardless of antibody test results to prevent infection.
- Keep physical distance – at least 6 feet or more from others
- Wear a cloth face covering when you must go out in public
- Wash your hands often with soap and water, for at least 20 seconds
- Monitor yourself and your family for COVID-19 symptoms
Where can I get more information on COVID-19?
Go to uclaheath.org/coronavirus for all of the latest COVID-19 information or call our patient hotline Monday to Friday, 7am to 7pm at 310-267-3300. Calls received outside of business hours will be returned the following business day.
Here are some additional COVID-19 quick links:
- UCLA Health clinical trials
- Convalescent Serum Project
- Stop COVID-19 Together data project
- COVID-19 FAQs
- Sign-up for health news & information
