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Anti-flu virus antibody, serum/plasma (qualitative, immunoassay)

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

This test checks for the presence of antibodies in your blood that your immune system makes to fight flu viruses, such as Influenza A or B. Antibodies indicate whether your body has been exposed to these viruses in the past.

Quick summary

["This test helps determine if you’ve had prior exposure to flu viruses, which can inform vaccination decisions or monitor immune response."]

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

Key facts at a glance

LOINC
7928-5
Short code
FLUAV Tex Ab Ser-aCnc
Synonyms
FLUAV Tex Ab Ser-aCnc
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 This Test Measures

The test detects specific antibodies (immunoglobulins) produced by your immune system in response to exposure to flu viruses. These antibodies are part of your body’s memory immune response, meaning your system has likely encountered the virus before. The test is qualitative, meaning it only tells you whether antibodies are present rather than their exact levels.

Why It’s Done

Doctors may order this test if you have symptoms of flu, have had recent exposure to someone with flu, or if you’re at higher risk for complications (e.g., elderly, immunocompromised). It can also be used to assess immune response after vaccination or to diagnose past infections.

How It’s Done

A small blood sample is drawn from a vein in your arm. The blood is then processed to detect the presence of flu-specific antibodies using an immunoassay method, which identifies the antibodies without measuring their exact concentration.

What to Expect Before the Test

No special preparation is needed. You may have some mild discomfort or bruising at the injection site, but this usually goes away quickly. If you’re on blood-thinning medication, let your doctor know before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Anti-Fluab Antibody (Qualitative)

Frequently asked questions

How long does it take to get results?
Results are typically available within 1 to 3 business days, depending on lab processing times. Your healthcare provider will contact you once results are ready.
What does a positive result mean?
A positive result means your body has detected flu antibodies, indicating you’ve likely been exposed to flu viruses in the past. This doesn’t necessarily mean you had active flu symptoms, but it confirms your immune system has mounted a response.
Can this test be used to diagnose active flu?
No, this test is qualitative and only detects past exposure. For diagnosing active flu, your doctor may use rapid flu tests or viral culture tests instead.
  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