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Influenza A/B Antibody

Published: July 27, 2026Updated: August 25, 2026

The Influenza A/B antibody test measures the presence and quantity of antibodies against influenza A and B viruses in the blood.

Quick summary

This test detects antibodies to diagnose recent or past influenza A and B infections.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
index
Clinical utility
diagnostic
Result kind
qualitative
FDA-cleared
Roche Influenza A/B, Abbott Influenza, Sofia Influenza
interpretation: {"text":"Negative for influenza A/B antibodies; no current or recent infection detected.","label":"Index < 0.8"}; {"text":"Positive for influenza A/B antibodies; likely recent or past infection.","label":"Index > 1.2"}

The Influenza A/B antibody test is a diagnostic tool used to identify past or recent infections with influenza A or B viruses. It measures the levels of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies specific to these viruses.

The presence of IgM antibodies typically indicates a recent infection, while IgG antibodies suggest a past exposure or vaccination. This test is particularly useful during flu seasons to confirm diagnoses.

Results are reported as an index value, with a reference range of 0–1. Values above 1 may indicate a current or recent infection, while values within the reference range suggest no current infection.

Frequently asked questions

How is the Influenza A/B antibody test performed?
The test is performed using a blood sample, which is analyzed in a laboratory to detect the presence of specific antibodies.
What does a positive result mean?
A positive result indicates the presence of antibodies, suggesting a recent or past infection with influenza A or B.
  1. 1
    CDC - Influenza TestingSource
  2. 2
    Mayo Clinic - Influenza TestsSource

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 25, 2026. · Read our editorial policy