Fluorescent Antibody Test for Antihuman Influenza A/B Antibodies (Serum/Plasma)
This test detects antibodies in your blood that your immune system produces in response to the influenza virus (types A or B). It helps determine if you’ve been exposed to the virus, even if you don’t yet have symptoms.
["This test can help identify past or recent exposure to the flu virus, aiding in diagnosis or monitoring immunity."]
Key facts at a glance
- LOINC
- 39303-3
- Short code
- FLUAV H2 Ab Titr Ser HAI
- Synonyms
- FLUAV H2 Ab Titr Ser HAI
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- hai
- 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 antibody technique to identify specific antibodies (IgG or IgM) against influenza A or B. These antibodies are part of your immune response to the virus. The presence of these antibodies suggests exposure, but they don’t confirm an active infection alone.
How the Test Works
A small blood sample is taken from your arm and sent to a lab. The sample is tested using a method that detects antibody presence by binding to labeled influenza virus particles. Fluorescence indicates a positive result, meaning your body has likely encountered the virus.
When You Might Need This Test
Your healthcare provider may recommend this test if you have symptoms of the flu (like fever, cough, or fatigue), if you’ve been exposed to someone with the flu, or if you’re in a high-risk group (e.g., elderly, immunocompromised, or pregnant). It’s also sometimes used in outbreaks or research settings.
What to Expect Before the Test
No special preparation is needed for this blood test. You may have a slight bruise or pinch at the injection site, but it typically resolves quickly. If you’re on blood-thinning medication, let your provider know before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results indicate exposure to the influenza virus, which can guide treatment decisions, such as antiviral medications if an active infection is suspected. However, antibody levels may take days to weeks to develop after exposure, so this test is most useful for identifying past exposure rather than recent illness. It’s not a substitute for a viral test (like PCR) to confirm an active flu infection.
Short name
Influenza Antibody Screening
Frequently asked questions
How long does it take to get results?
Can this test tell me if I currently have the flu?
Will I need to take any special steps if my test is positive?
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