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SARS-CoV-2 Immunoglobulin G (IgG) Antibody, Serum/Plasma

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

This test detects antibodies (specifically IgG) your immune system makes in response to exposure to the SARS-CoV-2 virus, which causes COVID-19. IgG antibodies are typically present weeks to months after infection.

Quick summary

["IgG antibodies indicate past infection and long-term immune protection (if present)."]

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

Key facts at a glance

LOINC
108788-1
Short code
SARS-CoV-2 IgA Msmt SerPl
Synonyms
SARS-CoV-2 IgA Msmt SerPl
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 Does This Test Measure?

This test measures the level of IgG antibodies in your blood that your immune system produces after encountering the SARS-CoV-2 virus. IgG is one type of antibody that helps your body fight infections and provides long-term immunity. The test uses a blood sample drawn from a vein, usually in your arm.

Why Might You Need This Test?

Doctors may order this test to confirm past COVID-19 infection, assess immune response, or evaluate exposure in individuals who have recovered from COVID-19 or are at higher risk of infection. It can also help monitor immune status in certain clinical scenarios.

How Is the Test Performed?

A healthcare provider will insert a needle into your arm to draw blood. The blood sample is then sent to a lab for analysis using an immunoassay method, which detects the presence of IgG antibodies against the virus.

What Are the Possible Results?

Results are typically reported as positive or negative. A positive result suggests you have developed IgG antibodies, indicating past infection. A negative result means no detectable IgG antibodies were found at this time.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Understanding IgG Antibodies

Short name

IgG Antibody to SARS-CoV-2

Frequently asked questions

How long do IgG antibodies last after COVID-19?
IgG antibodies can remain in your system for weeks to months after infection. Their duration can vary among individuals, and they may not provide lifelong immunity. Other factors, like vaccination status, can influence antibody levels and protection.
Can IgG antibodies protect me from getting COVID-19 again?
IgG antibodies may offer some protection against reinfection, but they are not guaranteed to prevent all future infections. Other factors, such as vaccination, boosters, and overall immune health, also play a role in protection.
What does a positive IgG result mean?
A positive IgG result means your immune system has likely encountered the SARS-CoV-2 virus in the past, producing antibodies to fight it. This does not necessarily mean you had symptoms or a confirmed diagnosis, but it indicates exposure.
  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