Review Article
Neonatal and Infantile Immune Responses to Encapsulated Bacteria and Conjugate Vaccines
Table 1
Characteristics of thymus-dependent and thymus-independent antigens
| Characteristics | Thymus-dependent | Thymus-independent type 1 | Thymus-independent type 2 |
| TH-cell activation | ++ | − | − | IgM-IgG switch | +, IgG1, IgG3 | +/−, IgM, IgG2 (low
quantities) | −, IgM | Booster response | ++ | − | Immune response in neonates | High (but lower than
in adults) | Intermediate | Low | Development of antibody responses | At birth | 3–18 m | 24 m | Examples | Protein antigens | LPS | PS |
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