Vaccines & Immunoglobulins

Introduction

• Immunobiologicals (vaccines, antisera, immunoglobulins) are biological products that reinforce immunological defence against infecting organisms or their toxins; immunization introduces an antigen to induce protection without causing disease.
• Two fundamental strategies: active immunization (vaccines act as antigens → recipient makes specific antibody and/or cell-mediated immunity, CMI) and passive immunization (readymade antibodies transferred from another person/animal).
• Vaccines and sera are public-health products: manufacture, quality control and sale are strictly state-supervised, potency standardised by bioassay, and most need cold-chain storage.
• Historical milestones — variolation (17th c.) → Jenner 1796 coined "vaccination" (Latin vacca, cow) using cowpox → Salk inactivated polio 1955, Sabin oral 1961 → smallpox eradicated (WHO, 1979), still the only globally eradicated vaccine-preventable disease.
• Vaccination prevents an estimated 3.5–5 million deaths/year; its public-health impact is rivalled only by clean drinking water.