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Fluorescent Immunoassay for Anti-Vaccinia Virus Antibodies (Serum/Plasma)

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

This test checks for antibodies against the vaccinia virus, which is used in vaccines like the smallpox vaccine. It helps determine if your immune system has recognized and responded to this virus.

Quick summary

["Assesses immune response to vaccinia virus exposure or vaccination."]

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

Key facts at a glance

LOINC
44563-5
Short code
FLUAV Ag Nose Ql
Synonyms
FLUAV Ag Nose Ql
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 produced by your immune system in response to exposure to the vaccinia virus. These antibodies are part of your body’s defense mechanism against the virus. The method used is a fluorescent immunoassay (FIA), which identifies these antibodies by binding to them and measuring fluorescence.

Why It’s Ordered

Doctors may order this test if you’ve had exposure to the vaccinia virus (e.g., from a vaccine or accidental contact) or if you’re being monitored for immunity after vaccination. It can also be used in research or public health surveillance.

Sample Collection and Preparation

A blood sample is taken from a vein in your arm. The serum or plasma is then processed and tested for the presence of antibodies. This test is typically done on fresh or stored serum/plasma samples.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small bruise or slight discomfort at the injection site, but it usually fades 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-Vaccinia Antibody (FIA)

Frequently asked questions

What does a positive result mean?
A positive result means your immune system has recognized the vaccinia virus and produced antibodies against it. This could mean you’ve been vaccinated, exposed to the virus, or both. It does not guarantee immunity against all strains or related viruses, but it confirms your body has mounted an immune response.
What does a negative result mean?
A negative result means no detectable antibodies were found in your sample. This could mean you have not been exposed to the vaccinia virus or your immune system did not produce enough antibodies to be detected. It does not rule out possible exposure or immunity, as antibody levels may vary over time.
Can this test be used for smallpox vaccination monitoring?
Yes, this test can be used to monitor immune response to vaccinia virus vaccines, such as those used in smallpox vaccination programs. However, it is not the primary method for confirming immunity and should be interpreted alongside clinical judgment and other factors, like vaccination history.
  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