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COVID-19 Evaluation Note (Serological Screening)

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

This test checks for antibodies in your blood that may indicate past exposure to COVID-19. Antibodies are proteins your immune system produces in response to the virus.

Quick summary

["This test helps determine if your body has developed immunity after infection or vaccination."]

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

Key facts at a glance

LOINC
94721-8
Short code
COVID-19 Eval note
Synonyms
COVID-19 Eval note
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
role
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

The test detects specific antibodies (immunoglobulins) produced by your immune system in response to the SARS-CoV-2 virus. These antibodies can appear in your blood several weeks after infection or vaccination. The test typically looks for two main types of antibodies: IgM and IgG. IgM antibodies usually appear first and decline over time, while IgG antibodies provide long-term immunity.

Why It’s Done

Healthcare providers may order this test to assess whether you’ve been exposed to COVID-19, evaluate your immune response to vaccination, or monitor immunity in high-risk groups. It’s also used in research or clinical studies to track antibody levels over time.

Sample Collection and Process

A small blood sample is drawn from your arm. The blood is processed to separate serum (the liquid part without blood cells) and tested for antibodies using an immunoassay method, which detects the presence and levels of specific proteins.

Interpretation and Limitations

Results can be positive (indicating antibodies), negative (no detectable antibodies), or inconclusive (depending on the test). Antibody levels may vary and decline over time. This test does not confirm current infection—it only shows past exposure or immunity. False positives or negatives can occur, especially with certain medical conditions or recent vaccinations.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

COVID-19 Antibody Screen

Frequently asked questions

Why might I need this test?
This test helps determine if you’ve developed immunity to COVID-19, which is important for understanding your risk of reinfection, especially if you’re in a high-risk group or planning travel. It can also guide decisions about vaccination boosters or precautions.
What does a positive result mean?
A positive result suggests your body has produced antibodies against COVID-19, likely from past infection or vaccination. This does not mean you are currently infected but indicates potential immunity. Follow-up testing or clinical advice may be needed to assess ongoing protection.
Can this test replace a COVID-19 PCR test?
No. Antibody tests detect past exposure or immunity, while PCR tests identify active infection. If you have symptoms or suspect recent exposure, a PCR test is the gold standard for diagnosing active 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