Test Catalog

Test Id : PN23M

Streptococcus pneumoniae IgG Antibodies, 23 Serotypes, Serum

Useful For
Suggests clinical disorders or settings where the test may be helpful

Assessing the IgG antibody response to active immunization with nonconjugated, 23-valent pneumococcal vaccines


Assessing the IgG antibody response to active immunization with conjugated 13-valent, 15-valent and 20-valent pneumococcal vaccines


Determining the ability of an individual to produce an antibody response to polysaccharide antigens, as part of the evaluation for humoral or combined immunodeficiencies

Method Name
A short description of the method used to perform the test

Bead-Based Multiplex Immunoassay

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

S. pneumoniae IgG Ab,23 serotypes,S

Lists additional common names for a test, as an aid in searching

Pneumococcal Antibody (IgG) 23 Serotype Panel

Strep Antibodies

Strep Pneumo Antibodies

Strep Pneumoniae Antibody

Strep Vaccine

Streptococcus Pneumoniae


Specimen Type
Describes the specimen type validated for testing


Ordering Guidance

This test is the preferred test for patients previously tested for Streptococcus pneumoniae serotypes (as part of follow up testing or part of pre/post vaccine assessment).


The preferred test for patients being evaluated for possible immunodeficiency or for assessment of pneumococcal vaccination response (initial evaluation) is PNTOR / Streptococcus pneumoniae IgG Antibodies, Total, with Reflex, Serum


The preferred test for patients previously tested for total Streptococcus pneumoniae antibodies (as part of follow up testing or part of pre/post vaccine assessment) is PNTO / Streptococcus pneumoniae IgG Antibodies, Total, Serum

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial 

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

0.4 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 21 days
Frozen 21 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Assessing the IgG antibody response to active immunization with nonconjugated, 23-valent pneumococcal vaccines


Assessing the IgG antibody response to active immunization with conjugated 13-valent, 15-valent and 20-valent pneumococcal vaccines


Determining the ability of an individual to produce an antibody response to polysaccharide antigens, as part of the evaluation for humoral or combined immunodeficiencies

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Streptococcus pneumoniae (S. pneumoniae) is a gram-positive bacterium that causes a variety of infectious diseases in children and adults, including invasive disease (bacteriemia and meningitis) and infections of the respiratory tract (pneumonia and otitis media).(1) More than 90 serotypes of S. pneumoniae have been identified, based on varying polysaccharides found in the bacterial cell wall. The serotypes responsible for disease vary with age and geographic location.


Bacterial polysaccharides induce a T-cell independent type II humoral immune response. In adults and older children, bacterial polysaccharides are effective in generating an immune response that results in production of IgG antibodies and generation of long-lived plasma cells and memory B cells.(2) S. pneumoniae purified polysaccharide vaccines (PPSV) that contain a total of 23 serotypes (1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F, and 33F) are available; these are referred to as PPSV23.(3) These 23 serotypes were included because, as a group, they account for approximately 90% of invasive pneumococcal infections. Antibody responses develop in approximately 75% to 85% of nonimmunocompromised adults and older children approximately 4 to 6 weeks following immunization with purified polysaccharide vaccines. A meta-analysis estimated an efficacy of 74% for prevention of invasive pneumococcal disease in adults vaccinated with PPSV23.(4) In contrast, immune responses to polysaccharide antigens in children younger than 2 years of age are generally weak.


Active immunization of children younger than 2 years requires vaccines prepared of polysaccharides conjugated to an immunogenic carrier protein (Corynebacterium diphtheria strain C7), which results in a T-cell dependent antibody response.(3) In children younger than age 6, prior to the availability of routine S. pneumoniae vaccination, 7 serotypes (4, 6B, 9V, 18C, 19F, and 23F) accounted for 80% of invasive disease and up to 100% of all isolates that were found to be highly resistant to treatment with penicillin. The first pneumococcal conjugated vaccine (PCV) available for children younger than age 2 contained these 7 serotypes (PCV7). The vaccine was highly effective, with invasive disease in children younger than age 5 reduced from 99 to 21 cases per 100,000 population from 1998 to 2008.(5) In addition, it was demonstrated that after PCV7 became part of the routine vaccination schedule, only 2% of invasive disease was associated with any of the serotypes present in the vaccine. Instead, approximately 61% of the invasive disease was caused by an additional 6 serotypes (1, 3, 5, 6A, 7F, and 19A). This led to development of a 13-valent conjugated vaccine, known as PCV13. More recently, additional pneumococcal conjugate vaccines have been approved, specifically 15-valent (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F, 33F) and 20-valent (1, 3, 4, 5, 6A, 6B, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, and 33F) vaccines, known as PCV15 and PCV20, respectively.


Conjugated pneumococcal vaccination is included in the routine childhood schedule, with 4 doses of PCV13 or PCV15 administered at 2, 4, 6, and 12 to 15 months.(6) For adults younger than 65 years, a single dose of PCV20 or a single dose of PCV15 followed 1 year later with a single dose of PPSV23 is recommended.(7) This same pneumococcal vaccination strategy is recommended for adults 19 to 64 years of age with immunocompromising conditions, cochlear implants, cerebrospinal fluid leaks, or other chronic health conditions.


Patients with intrinsic defects in humoral immunity, such as common variable immunodeficiency, may have impaired antibody responses to pneumococcal vaccination.(8,9) Selective antibody deficiency is a recognized clinical entity in patients older than 2 years of age and is characterized by recurrent bacterial respiratory infections, absent or subnormal antibody response to a majority of polysaccharide antigens, and normal or increased immunoglobulin concentrations, including IgG subclasses, in the context of intact humoral response to protein antigens. In several other primary immunodeficiencies, including Wiskott-Aldrich syndrome, autoimmune lymphoproliferate syndrome, and DiGeorge syndrome, IgG subclass deficiencies may also result in impaired antibody responses to polysaccharide antigens.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Results are reported in mcg/mL



Normal value

1 (1)

> or =1.0

2 (2)

> or =1.0

3 (3)

> or =1.0

4 (4)

> or =1.0

5 (5)

> or =1.0

8 (8)

> or =1.0

9N (9)

> or =1.0

12F (12)

> or =1.0

14 (14)

> or =1.0

17F (17)

> or =1.0

19F (19)

> or =1.0

20 (20)

> or =1.0

22F (22)

> or =1.0

23F (23)

> or =1.0

6B (26)

> or =1.0

10A (34)

> or =1.0

11A (43)

> or =1.0

7F (51)

> or =1.0

15B (54)

> or =1.0

18C (56)

> or =1.0

19A (57)

> or =1.0

9V (68)

> or =1.0

33F (70)

> or =1.0

Provides information to assist in interpretation of the test results

As a general guideline, nonimmunocompromised adults develop IgG antibodies approximately 4 to 6 weeks following nonconjugated vaccination.


Either of the following conditions is consistent with a normal response to Streptococcus pneumonia vaccination:

1. When comparing pre- and post-vaccination samples, antibody concentrations increased by at least 2-fold for

a. >50% of serotypes in children <6 years of age

b. >70% of serotypes for individuals >6 years of age


2. In either a pre- or post-vaccination sample, antibody concentrations >/= 1.0 mcg/mL for

a. >50% of serotypes for children <6 years of age

b. >70% of serotypes for individuals >6 years of age

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

The humoral immune response to Streptococcal pneumoniae vaccination is affected by multiple factors, including age, immune status, vaccination history, prior infections, and carrier status.


Protective concentrations of IgG antibodies, or those required to prevent infection from S. pneumoniae, have not been defined for any serotype.


Quantitation of the IgG antibody response to pneumococcal serotypes does not provide any information on the functional capacity of the serotype-specific antibodies generated (opsonization efficiency).


IgG antibodies specific for the 23 serotypes included in PPSV23 are measured in this test; except for serotype 6A, IgG antibodies specific for all the serotypes in PCV13, PCV15, and PCV20 are measured in this test.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Weisberg SS: Pneumococcus. Dis Mon 2007 October;53(10):495-502

2. Grabenstein JD and Manoff SB. Pneumococcal polysaccharide 23-valent vaccine: long-term persistence of circulating antibody and immunogenicity and safety after revaccination in adults. Vaccine. 2012;30(30):4435-4444

3. Musher DM, Anderson R, Feldman C. The remarkable history of pneumococcal vaccination: an ongoing challenge. Pneumonia. 2022;14(1):5

4. Moberley S, Holden J, Tatham DP, Andrews RM. Vaccines for preventing pneumococcal infection in adults. Cochrane Database Syst Rev. 2013;2013(1):CD000422

5. Paradiso PR. Advances in pneumococcal disease prevention: 13-valent pneumococcal conjugate vaccine for infants and children. Clin Infect Dis. 2011;52(10):1241-1247

6. Kobayashi M, Farrar JL, Gierke R, et al. Use of 15-valent pneumococcal conjugate vaccine and 20-valent pneumococcal conjugate vaccine among U.S. adults: updated recommendations of the Advisory Committee on Immunization Practices – United States, 2022. MMWR Morb Mortal Wkly Rep. 2022;71(4):109-117

7. Kobayashi M, Farrar JL, Gierke R, et al. Use of 15-valent pneumococcal conjugate vaccine among U.S. children: updated recommendations of the Advisory Committee on Immunization Practices – United States, 2022. MMWR Morb Mortal Wkly Rep. 2022;71(37):1174-1181

8. Bonilla RA, Khan DA, Ballas ZK, et al. Practice parameter for the diagnosis and management of primary immunodeficiency. J Allergy Clin Immunol. 2015;136(5):1186-1205

9. Orange JS, Ballow M, Stiehm ER, et al. Use and interpretation of diagnostic vaccination in primary immunodeficiency: a working group report of the Basic and Clinical Immunology Interest Section o the American Academy of Allergy, Asthma and Immunology. J Allergy Clin Immunol. 2012;130(3 Suppl):S1-S24

Method Description
Describes how the test is performed and provides a method-specific reference

IgG antibodies to Streptococcus pneumoniae serotypes are measured by microsphere photometry (also known as bead-based multi-plex immunoassay) using pneumococcal polysaccharides conjugated to MagPlex microspheres.


This assay detects IgG antibodies to different serotypes of S. pneumoniae. The serotype-specific antibodies bound in the first stage of the assay are detected with R-phycoerythrin-conjugated, anti-human IgG antibody in the second stage of the assay.


Pneumococcal polysaccharides are modified with 4-(4,6-dimethoxy[1,3,5]triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) and conjugated to magnetic carboxylated polystyrene microparticles (hereinafter referred to as magnetic beads) that have been dyed into spectrally distinct regions to be identified by the Luminex FlexMap 3D (FM3D) instrument.  A mixture of 24 different beads (23 coupled to a different pneumococcal polysaccharide and 1 that is not coupled, to serve as a check for non-specific binding) is prepared in 1% BSA in PBS.


Standards and controls are prepared from pools of patient serum that have previously detected antibodies for the 23 serotypes of S. pneumoniae. A dilution series of standard, controls, and patient sera are added to a microwell plate.


An equal amount of the bead mixture is added and allowed to incubate. The plate is washed using 1% BSA in PBS on a magnetic plate washer to remove unbound material. A substrate containing a reporter molecule, R-phycoerythrin conjugated anti-human IgG antibody, is added to the plate. After incubation, the plate is read on the Luminex FM3D where the magnetic beads are differentiated and quantitated by 2 separate lasers. The red diode laser (635 nm) excites the fluorescent dyes contained within the beads, and the green laser (532 nm) excites the reporter molecule bound to the bead surface.  Data reduction software is used to quantify the amount of IgG antibody in unknown samples by correlation to a standard curve using a 5-Parameter Logistic (PL) curve fit.(Unpublished Mayo method)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

4 to 6 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

3 months

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

86317 x 23

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
PN23M S. pneumoniae IgG Ab,23 serotypes,S 42366-5
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
620316 Serotype 1 (1) 85954-6
620317 Serotype 2 (2) 86039-5
620318 Serotype 3 (3) 86080-9
620319 Serotype 4 (4) 86107-0
620320 Serotype 5 (5) 86130-2
620321 Serotype 8 (8) 86147-6
620322 Serotype 9N (9) 86169-0
620323 Serotype 12F (12) 85977-7
620324 Serotype 14 (14) 85991-8
620325 Serotype 17F (17) 86009-8
620326 Serotype 19F (19) 86024-7
620327 Serotype 20 (20) 86045-2
620328 Serotype 22F (22) 86052-8
620329 Serotype 23F (23) 86064-3
620330 Serotype 6B (26) 27118-9
620331 Serotype 10A (34) 86098-1
620332 Serotype 11A (43) 86122-9
620333 Serotype 7F (51) 25296-5
620334 Serotype 15B (54) 40973-0
620335 Serotype 18C (56) 27395-3
620336 Serotype 19A (57) 40974-8
620337 Serotype 9V (68) 30153-1
620338 Serotype 33F (70) 40969-8
620404 Interpretation 69048-7

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports