passive immunity

Syllable breakdown

Dictionary meaning

protection against infection conferred by the transfer of pre-formed antibodies from one individual to another, without requiring the recipient's own immune system to generate an active response to the pathogen; passive immunity occurs naturally through the transfer of maternal IgG antibodies across the placenta to the foetus and through immunoglobulins in breast milk, providing newborns with protection during the period before their own adaptive immune system matures; it can also be conferred medically through the administration of immune serum, monoclonal antibodies, or hyperimmune immunoglobulin preparations for post-exposure prophylaxis or the treatment of certain infections and toxin exposures