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Pneumococcal Antibody Titration (Serum) by Agglutination

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

This test measures the amount of antibodies your body produces in response to pneumococcal bacteria, which can cause serious infections like pneumonia.

Quick summary

["Helps assess immune response to pneumococcal vaccination or infection."]

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

Key facts at a glance

LOINC
91896-1
Short code
M pneumo Ab Titr Ser Aggl
Synonyms
M pneumo Ab Titr Ser Aggl
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
aggl
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

Why This Test Is Done

Your healthcare provider may order this test if you’ve had a pneumococcal infection, are at high risk for pneumococcal disease (e.g., due to weakened immunity), or if you’re being evaluated for vaccine effectiveness. It can also help monitor immune function after vaccination.

How the Test Works

A blood sample is taken from a vein in your arm. The serum is then tested for specific antibodies against pneumococcal bacteria using an agglutination method, which detects clumping reactions that indicate antibody presence.

Sample Collection and Preparation

The test uses serum from your blood. No special preparation is needed, but fasting may be advised depending on other tests ordered with it.

What to Expect After Testing

Results are typically reported as a titer value (e.g., 1:8, 1:64), showing the highest dilution of serum that still causes agglutination. Higher values suggest a stronger immune response.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Pneumococcal Antibody Level

Frequently asked questions

What Does a Low or High Result Mean?
A low titer may indicate insufficient immunity to pneumococcal bacteria, especially after vaccination, or possible recent infection. A high titer suggests a strong immune response, often seen post-vaccination or after exposure.
When Might Results Be Abnormal?
Abnormal results (depending on clinical context) could signal immune deficiency, inadequate vaccination response, or active infection. Your provider will interpret results in relation to your medical history and symptoms.
How Long Until Results Are Ready?
Results are usually available within 1–3 business days, but timing may vary. Follow-up with your healthcare provider to discuss findings.
  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