Vaccines & Immunoglobulins

Vaccines & Immunoglobulins

1. Definition, scope & historical perspective

• Immunobiologicals (vaccines, antisera, immunoglobulins) are biological products that reinforce the immunological defence of the body against infecting organisms or their toxins (KDT 8e Ch.70, p.978).
• Immunization is the process of introducing an antigen into the body to induce protection against an infectious agent without causing disease; an antigen is a substance that induces an immune response (DiPiro 12e Ch.147, p.2115).
• Two fundamental strategies (KDT 8e Ch.70, p.978; G&G 14e Ch.40, pp.795–6):
  • Active immunization — vaccines act as antigens that induce the recipient to produce specific antibodies and/or cell-mediated immunity (CMI). More efficacious and longer-lasting, but needs a latent period of one to many weeks; purely prophylactic.
  • Passive immunization — readymade antibodies (antisera, immunoglobulins) produced by another person/animal are transferred to the recipient. Affords immediate but temporary protection; can be curative as well as prophylactic.
• Acutely ill, debilitated or immunocompromised individuals may not generate an adequate antibody response and require passive protection (KDT 8e Ch.70, p.978).
• Vaccines and sera are potentially dangerous products used mainly in public-health programmes; their manufacture, quality control, distribution and sale are strictly state-supervised, standardised by bioassay, and need cold-chain storage to maintain potency (KDT 8e Ch.70, p.978).
• Historical milestones (G&G 14e Ch.40, pp.793–4):
  • Variolation against smallpox documented from the 17th century (Emperor K'ang of China); Lady Mary Montagu (Constantinople, 1716–18); Boston program by Cotton Mather & Zabdiel Boylston. Variolation mortality ~2–3% vs ~20–30% from natural smallpox.
  • Edward Jenner (1796) coined "vaccination" (Latin vacca, cow); used cowpox to protect against smallpox — the first use of a related, less-harmful disease to immunize.
  • Pasteur and Koch established the microbe–disease link; aluminium became the first demonstrated adjuvant (immune system cells identified ~1890; antibodies & hyperimmune serum discovered shortly after).
  • Salk inactivated (injected) poliovaccine, 1955; Sabin oral attenuated poliovaccine, 1961 → U.S. polio cases fell from 35,000 (1955) to 161 (1961).
  • Smallpox declared eradicated by WHO in 1979 — the only vaccine-preventable human disease globally eradicated to date (G&G 14e Ch.40, p.794; Harrison 22e Ch.129, p.1002).
• Impact of vaccination is rivaled in public-health terms only by clean drinking water (Katzung 16e App.1, p.1255). Vaccinations prevent an estimated 3.5–5 million deaths/year globally (Harrison 22e Ch.129, p.1003). 21 diseases are now routinely vaccine-preventable in the U.S. (Harrison 22e Ch.129, p.1001, Table 129-1).