Passive immunity

Definition

Passive immunity is the temporary immunity acquired by the direct transfer of antibodies from another individual or source. It provides immediate but short-term protection against pathogens.

5 Must Know Facts For Your Next Test

1. Passive immunity can be naturally acquired, such as through mother-to-child antibody transfer during breastfeeding.
2. It can also be artificially acquired through treatments like antibody injections (e.g., immunoglobulin therapy).
3. Unlike active immunity, passive immunity does not involve the activation of the recipient's immune system and therefore does not produce memory cells.
4. Passive immunity is crucial in providing immediate protection for individuals who are immunocompromised or exposed to a disease for which they lack immunity.
5. The duration of passive immunity typically lasts only a few weeks to months, depending on the half-life of the antibodies transferred.

Review Questions

• What is the primary difference between passive and active immunity?
• How can passive immunity be naturally acquired?
• Why doesn't passive immunity result in long-term protection?

Related terms

Active Immunity: Immunity resulting from the activation of an individual's own immune system, producing memory cells for long-term protection.

Antibodies: Y-shaped proteins produced by B-cells that neutralize pathogens or mark them for destruction by other immune cells.

Immunoglobulin Therapy: A medical treatment involving the injection of pooled antibodies to provide immediate but temporary protection against diseases.