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COVID-19 Antibody Test (Serum/Plasma) – Immunoassay (Qualitative)

Published: August 9, 2026Updated: August 16, 2026

This test checks for antibodies in your blood that your immune system produces after exposure to the COVID-19 virus, either from infection or vaccination.

Quick summary

Determines if your body has developed immunity to COVID-19.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
103569-0
Short code
ISTHERESIDENTSCOVID19VACCINATIONUPTODATE
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
cms-assessment
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

Antibodies are proteins your immune system makes to fight off infections. If you’ve been exposed to COVID-19 (through infection or vaccination), your body may produce detectable antibodies. This test detects the presence of these antibodies, which can indicate immunity.

Why It’s Ordered

Doctors may order this test to assess whether you’ve developed immunity after vaccination, monitor immunity in high-risk individuals, or evaluate past exposure in cases of suspected reinfection.

Sample Collection and Preparation

A blood sample is drawn from your arm. The blood is processed into either serum (liquid after clotting) or plasma (liquid after centrifugation), then tested for specific COVID-19 antibodies using an immunoassay method.

Interpreting Results

Results are qualitative (positive or negative). A positive result suggests your immune system has recognized and responded to the virus, while a negative result means antibodies were not detected in this sample.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

COVID Antibody Screen

Frequently asked questions

Your immune response to COVID-19 antibodies may change over time. A positive result does not guarantee lifelong immunity but indicates a past or current immune response. This test is not a substitute for vaccination status verification in some settings.
This test does not confirm active COVID-19 infection. If you have symptoms or suspect exposure, consult your healthcare provider for additional testing (e.g., PCR or antigen tests).
How long does it take to get results?
Results are typically available within 1–3 business days, depending on lab processing times. Follow-up instructions from your healthcare provider will guide next steps.
Can I get this test if I’m not vaccinated?
Yes, this test can be performed regardless of vaccination status to check for antibodies from prior infection. However, vaccination remains the primary method to ensure long-term protection.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy