Passive immunity via pathogen- or autoantibody-targeting antibodies

Passive immunity via pathogen/autoantibody targeting refers to the therapeutic administration of preformed antibodies from another individual—human or animal—to provide immediate but temporary protection against infectious agents or neutralize harmful autoantibodies. This process does not involve stimulation of the recipient’s own adaptive immune system and therefore does not confer lasting immunological memory. Natural forms include maternal antibody transfer across the placenta and through breast milk; artificial forms involve administration of pooled human plasma-derived immunoglobulins, animal antisera, convalescent plasma from recovered patients, or laboratory-produced monoclonal antibodies. Indications range from post-exposure prophylaxis after contact with certain viruses/bacteria/toxins to acute treatment in individuals unable to mount an effective immune response themselves. This entry is not a molecular target like a receptor/enzyme/transporter but rather describes an entire therapeutic strategy involving many possible targets depending on the specificity of administered antibodies. Therefore it should not be considered a canonical drug target entity. "Passive immunization provides similar...protection by 'donating' antibodies...to a vulnerable individual." "Several products have been approved...for passive immunization...including antibodies against botulism, diphtheria..." "Unlike vaccination...passive immunization does not result in immunological memory."

Other names

Passive immunizationAntibody-mediated passive immunityAntiserum therapyImmunoglobulin therapy

Passive immunization works by introducing exogenous antibodies that bind to and neutralize specific pathogens or their toxins. These antibodies can block pathogen entry into cells (“neutralizing”), promote clearance by the immune system (“opsonization”), activate complement pathways leading to lysis of microbes/toxins, or modulate autoimmune processes by binding autoantibodies.