Post-exposure prophylaxis with Immunoglobulins
💡 Passive Immunity = immediate protection using pre-formed antibodies (immunoglobulins).
Always seek expert guidance (see BNF).
🧬 Key Principles
- Protection is given by injecting antibodies from immune donors (plasma/serum).
- Onset = immediate ⏱️, but short-lived (weeks); can be repeated if required.
- Immunoglobulins = human origin; Antisera = animal origin (rarely used due to serum sickness risk).
- Reactions to human immunoglobulin are rare.
🔑 Types of Passive Immunity
- Human normal immunoglobulin (HNIG) – pooled antibodies from >1000 donors.
- Disease-specific immunoglobulins – enriched against a single pathogen.
👥 Human Normal Immunoglobulin (HNIG)
- Sterile, concentrated IgG preparation from pooled plasma.
- Contains antibodies to common viruses: hepatitis A, measles, mumps, rubella, varicella, etc.
- Global shortage → UK Demand Management Programme (see ivig.nhs.uk, Gov.uk guidance).
📌 Clinical Uses of HNIG
- Hepatitis A → post-exposure prophylaxis (unvaccinated contacts).
- Measles → exposed child with severe risk factors (e.g. heart/lung disease, immunosuppression).
🎯 Human Specific Immunoglobulins
- 🦠 Hepatitis B Immunoglobulin (HBIG) → post-exposure (needle-stick, sexual exposure, neonates of HBsAg+ mothers).
- 💉 Tetanus Immunoglobulin (TIG) → high-risk wounds if immunisation incomplete/unknown.
- 🐕 Rabies Immunoglobulin → post-exposure prophylaxis (animal bite/scratch in endemic areas).
- 🐔 Varicella Zoster Immunoglobulin (VZIG) → high-risk exposure (immunosuppressed, neonates, pregnant women <20 wks).