Version July 2025
| Underlying mechanism | Medical condition |
| Reduced capacity to make antibody to pneumococcal capsular polysaccharide | Genetically determined agammaglobulinemia |
| Genetically determined hyporesponsiveness to pneumococcal polysaccharides | |
| Acquired ("common variable") hypogammaglobulinemia | |
| Selective IgG subclass deficiency | |
| Aging | |
Diseases that specifically affect B-cell responses:
| |
Diseases associated with loss of antibody:
| |
Immunosuppressive therapy:
| |
| Insufficient number of PMNs | Cyclic or drug-induced neutropenia |
| Leukemia | |
| Aplastic anemia | |
| Abnormal PMN function | Diabetes mellitus (poorly controlled) |
| Chronic liver disease (also multifactorial) | |
| Chronic renal disease (also multifactorial) | |
| Glucocorticoids | |
| Altered splenic function | Splenectomy |
| Hyposplenism | |
| Hemoglobinopathy | |
| Multifactorial (also poorly defined) | Malnutrition |
| Alcohol use disorder | |
| Other chronic diseases | |
| Hospitalization | |
| Physical or emotional stress | |
| Systemic lupus erythematosus | |
| Increased exposure | Daycare centers |
| Military training camps | |
| Prisons | |
| Homeless shelters | |
| Anatomic susceptibility | Cerebrospinal fluid leak |
| Devices present in subarachnoid space | |
| Cochlear implant | |
| Inflammatory joint disease | |
| Active or recent respiratory viral infection |
