Immunization is classified into active and passive forms based on whether protection arises from the recipient's own generated immune response or from transfer of pre-formed antibodies. Active immunization introduces antigen to induce an in vivo primary immune response that generates antigen-specific memory T- and B-cells, producing a delayed but long-lasting protection with both cell-mediated and humoral components; passive immunization delivers pre-formed antibody for immediate but short-lived, humoral-only protection limited by antibody half-life. This is a concept within immunology, specifically vaccinology, and relates to the broader theory of adaptive immune memory and primary versus secondary immune responses.
Immunization is classified into active and passive forms based on whether protection arises from the recipient's own generated immune response or from transfer of pre-formed antibodies. Active immuni…