Passive immunity

Definition

Passive immunity is the transfer of active humoral immunity in the form of ready-made antibodies from one individual to another. It provides immediate, but temporary protection against pathogens.

5 Must Know Facts For Your Next Test

1. Passive immunity can be naturally acquired through maternal antibodies transferred via placenta or breast milk.
2. It can also be artificially acquired through immunoglobulin therapies and antitoxins.
3. Unlike active immunity, passive immunity does not involve the host's immune system producing its own antibodies.
4. Passive immunity offers immediate protection but generally lasts only a few weeks to months.
5. Passive immunity does not create memory cells, thus there is no long-term immunological memory.

Review Questions

• What are two ways passive immunity can be acquired?
• How does passive immunity differ from active immunity in terms of antibody production and duration?
• Why doesn't passive immunity provide long-term protection?

Related terms

Active Immunity:

Immunity resulting from the activation of an individual's own immune system, leading to the production of memory cells.

Antibodies:

Proteins produced by B cells that recognize and neutralize specific antigens.

Immunoglobulin Therapy: Treatment involving the injection of pre-made antibodies to provide temporary protection or treatment for certain diseases.