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COVID-19 Antibody Screening Test (Serum/Plasma)

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

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

Quick summary

["Helps determine 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
99349-3
Short code
HASORHADCOVID19
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Antibodies Are Measured?

This test typically measures antibodies like IgG and IgM that your immune system creates in response to the SARS-CoV-2 virus. IgM antibodies usually appear shortly after infection and decline over time, while IgG antibodies persist longer, indicating long-term immunity.

Why Might You Need This Test?

Doctors may recommend this test if you’ve had COVID-19 symptoms, were exposed to the virus, or received a COVID-19 vaccine to confirm immunity or monitor your immune response.

What to Expect Before the Test

No special preparation is needed. A healthcare provider will collect a blood sample from a vein in your arm. The test is usually done in a lab and results are ready within a few days.

What the Results Mean

Positive results indicate the presence of antibodies, suggesting past infection or vaccination. Negative results mean no detectable antibodies at this time, but this doesn’t rule out recent infection.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test helps assess immunity status but isn’t a definitive test for active infection. It’s important to follow public health guidelines for ongoing protection.

Short name

COVID Antibody Test

Frequently asked questions

Can this test detect COVID-19 if I’m currently sick?
No, this test measures antibodies, not the virus itself. If you have active COVID-19 symptoms, you should use a different rapid antigen or PCR test instead.
How long do antibodies stay in my blood after infection?
IgM antibodies typically last a few months, while IgG antibodies may remain detectable for months or even years, but levels can vary widely between individuals.
Does this test replace a COVID-19 vaccine?
No, this test confirms immunity but doesn’t replace vaccination. Vaccination remains the best way to prevent serious illness and long-term complications from COVID-19.
  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