SARS-CoV-2 IgA Antibody (Serum/Plasma) – Immunoassay
This test detects antibodies of the IgA type that your immune system produces in response to exposure to the virus that causes COVID-19. IgA antibodies can appear in the blood and respiratory tract shortly after infection.
["IgA antibodies help your body fight the virus and may indicate past or recent exposure to SARS-CoV-2."]
Key facts at a glance
- LOINC
- 94720-0
- Short code
- SARS-CoV-2 IgA SerPl IA-aCnc
- Synonyms
- SARS-CoV-2 IgA SerPl IA-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- 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?
IgA antibodies are part of your immune system’s defense. They are typically found in mucous membranes (like those in the nose and throat) and in blood. This test measures IgA antibodies specific to the spike protein of the SARS-CoV-2 virus, which helps the virus enter human cells. Detecting these antibodies can help determine if you’ve been exposed to the virus, even if you didn’t develop symptoms or have recovered.
Why Might You Need This Test?
Your healthcare provider may order this test if you have symptoms of COVID-19, have been exposed to someone with the virus, or if you are part of a study or screening program. It can also be used to monitor immune response after vaccination or infection.
How Is This Test Performed?
A blood sample is taken from a vein in your arm. The blood is then tested using an immunoassay method, which detects the presence of IgA antibodies against the virus. The test is usually done in a laboratory and results are available within a few days.
What Are Possible Results?
Results may be reported as positive, negative, or indeterminate. A positive result suggests the presence of IgA antibodies, which may indicate past or recent exposure to the virus. A negative result means no detectable IgA antibodies were found at the time of testing. An indeterminate result may require further testing.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
IgA Antibody to SARS-CoV-2
Frequently asked questions
IgA antibodies can appear before other types of antibodies (like IgG) and may be more prevalent in the early stages of infection. They can also be present in people who have recovered from COVID-19 or those who have been vaccinated. However, IgA antibodies alone may not always indicate a current infection, as they can also be produced in response to other viral exposures or as part of a normal immune response.
IgA antibodies may begin to appear within a few days to two weeks after exposure to the virus. However, detection timing can vary depending on the individual’s immune response. This test is not typically used to diagnose an active infection but can help assess past exposure or immune response.
Yes, IgA antibodies can be detected after vaccination, especially in the early stages. They are part of the immune response and may be found in both vaccinated individuals and those who have recovered from infection.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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