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 short-term protection against infectious agents.

5 Must Know Facts For Your Next Test

1. Passive immunity can be acquired naturally, such as through maternal antibodies transferred to a baby via the placenta or breast milk.
2. It can also be acquired artificially through immunoglobulin or antiserum injections.
3. Unlike active immunity, passive immunity does not involve the recipient's immune system producing its own antibodies.
4. Passive immunity is typically short-lived, lasting only a few weeks to months because the antibodies are eventually degraded by the recipient's body.
5. It is often used in cases where immediate protection is needed, such as after exposure to a potentially deadly pathogen or toxin.

Review Questions

• What are two ways passive immunity can be acquired?
• How does passive immunity differ from active immunity in terms of antibody production?
• Why is passive immunity considered short-lived compared to active immunity?

Related terms

Active Immunity:

Immunity developed by an individual's own immune system through exposure to a pathogen or vaccination.

Immunoglobulin:

A type of antibody used in passive immunization for providing immediate protection against diseases.

Antiserum: A blood serum containing specific antibodies against certain antigens used for passive immunization.