Vaccines and Sera

VACCINES AND SERA

Vaccines and sera are biological products which act by reinforcing the immunological defence of the body against foreign agencies (mostly infecting organisms or their toxins).

Vaccines impart active immunity—act as antigens which induce production of specific antibodies by the recipient himself.

Antisera and Immuneglobulins impart passive immunity—readymade antibodies (produced by another person or animal who has been actively immunized) are transferred.

Active immunization is more efficacious and longer lasting than passive immunization, but the former needs a latent period of one to many weeks, whereas the latter affords immediate protection. Antisera are, therefore, curative also, whereas vaccines are only prophylactic. Acutely ill, debilitated or immunocompromised individuals may not be able to generate an adequate antibody response and require passive protection.

Vaccines and sera are potentially dangerous products and mostly used in public health programmes—their manufacture, quality control, distribution and sale is strictly supervised by State health authorities. These biologicals are standardized by bioassay and need storage in cold to maintain potency.