Fluorescent Immunoassay for Anti-Viral Antibodies (e.g., Influenza Virus Antibodies)
This test detects antibodies your immune system produces in response to exposure to the influenza virus. It helps determine if you’ve had prior infection or vaccination against flu.
["Checks for past flu exposure or immunity status via antibody detection."]
Key facts at a glance
- LOINC
- 6437-8
- Short code
- FLUAV+FLUBV Ag Spec Ql IA
- Synonyms
- FLUAV+FLUBV Ag Spec Ql IA
- 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
- 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 uses a fluorescent immunoassay to identify specific antibodies (IgG and/or IgM) against influenza viruses. These antibodies develop after infection or vaccination and signal your body’s immune response. The method detects these antibodies in a blood sample to confirm exposure or immunity.
Why It’s Ordered
Doctors may order this test to assess whether you’ve been exposed to the flu, evaluate immunity after vaccination, or investigate unexplained flu-like symptoms in the context of prior infection. It’s also used in research or outbreak investigations.
Sample Collection and Preparation
A blood sample is drawn from your arm, typically in a vein. The sample is processed and sent to a lab for fluorescent immunoassay testing. Results are usually reported as qualitative (positive/negative) or semi-quantitative (titer levels).
What to Expect Before the Test
No special preparation is needed, but inform your healthcare provider about recent illnesses, vaccinations, or medications that might affect results. Avoid alcohol for 24 hours before testing if instructed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Influenza Antibody Test (FIA)
Frequently asked questions
This test is primarily useful for identifying past exposure to influenza viruses, distinguishing between natural infection and vaccination immunity, or supporting diagnostic considerations in clinical settings. IgG antibodies indicate long-term immunity, while IgM may suggest recent infection.
What does a positive result mean? A positive result indicates the presence of antibodies against the influenza virus, suggesting prior exposure (infection or vaccination). However, it does not confirm active illness at the time of testing.
Does this test replace a flu shot? No, this test measures antibodies and does not provide active immunity. A flu shot is necessary for protection against future infections.
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