Fluorescent Immunoassay for Anti-Viral Antibodies (e.g., Influenza Virus Neutralizing Antibodies)
This test measures antibodies your immune system produces in response to a previous infection with the influenza virus. It helps determine if you’ve been exposed to flu viruses like A or B.
["Checks for past flu exposure to guide vaccination or infection tracking."]
Key facts at a glance
- LOINC
- 85476-0
- Short code
- FLUAV+FLUBV+RSV RNA pnl Up resp NAA+pr
- Synonyms
- FLUAV+FLUBV+RSV RNA pnl Up resp NAA+pr
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- 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) in your blood that target influenza viruses. These antibodies develop after your body has encountered the virus, either through infection or vaccination. The presence of these antibodies suggests your immune system has recognized and responded to the flu virus.
Why It’s Done
Healthcare providers may order this test to confirm past exposure to influenza, assess immune response to vaccination, or investigate symptoms of flu-like illness in individuals with uncertain exposure history.
Sample Collection and Preparation
A blood sample is drawn from a vein in your arm. The blood is processed to separate serum or plasma, which is then tested for antibody levels using a fluorescent immunoassay method. This method detects antibodies that bind to influenza virus proteins.
What to Expect Before the Test
No special preparation is needed. You may eat and drink normally before the test. If you’re on blood-thinning medication, inform your provider beforehand.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results indicate your immune system has mounted an antibody response to influenza, which can be useful for diagnosing past infection, evaluating vaccine efficacy, or monitoring immune status in high-risk groups. However, antibody levels alone do not confirm active flu infection; they reflect prior exposure. Results should be interpreted alongside clinical symptoms and other diagnostic information.
Short name
Influenza Antibody Test (FIA)
Frequently asked questions
Will this test show if I currently have the flu?
How long after exposure might I see positive results?
Can this test be used to check if my flu vaccine worked?
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