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Serum Antibody Test for Pneumococcal Serotypes (Qualitative Immunoassay)

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

This test measures antibodies in your blood that target different types of *Streptococcus pneumoniae* (pneumococcus), a common cause of pneumonia, meningitis, and other infections.

Quick summary

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

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

Key facts at a glance

LOINC
42365-7
Short code
S pneum 4 serotypes IgG Pnl Ser-mCnc
Synonyms
S pneum 4 serotypes IgG Pnl Ser-mCnc
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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

Doctors may order this test if you’ve had recent pneumococcal vaccination, have symptoms of pneumonia or meningitis, or are at higher risk for pneumococcal infections (e.g., due to weakened immune system, age, or chronic health conditions). It helps confirm whether your body produced protective antibodies against specific pneumococcal strains.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. The test checks for antibodies in your serum (liquid part of blood). Results are qualitative (yes/no) rather than quantitative, meaning it only tells whether antibodies were detected, not their exact levels.

What the Results Mean

A positive result indicates the presence of antibodies against certain pneumococcal serotypes. This may suggest prior infection, vaccination, or both. A negative result means no detectable antibodies were found for those serotypes. Results alone don’t diagnose illness but support clinical decisions.

Possible Side Effects or Risks

Minor side effects from blood drawing (e.g., bruising, slight pain) are rare but possible. No other risks are associated with this test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Pneumococcal Antibody Screen (Serum)

Frequently asked questions

What does a positive result mean for my health?
A positive result suggests your immune system has recognized and responded to those specific pneumococcal strains. This could mean you’ve had prior infection, received the pneumococcal vaccine, or both. It doesn’t replace other diagnostic tests (like cultures) but may help guide treatment or vaccination decisions if needed.
Could a negative result mean I’m at risk for pneumococcal infection?
A negative result for these serotypes means no antibodies were detected for those strains. However, pneumococcal infections can involve multiple serotypes, and other factors (like immune status) may still increase your risk. Discuss your risk factors with your healthcare provider to determine if further testing or preventive measures are needed.
Is this test the same as a pneumococcal vaccine check?
This test checks for antibodies *after* exposure (infection or vaccination), not whether you’re currently immune. Vaccine effectiveness varies by person and may require booster doses. Your doctor may recommend this test if you’re unsure about your immune response or at higher risk.
  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