Primary immune response

Definition

Primary immune response is the body's initial reaction to a foreign antigen. It involves the activation of naïve B and T cells and typically takes several days to develop fully.

5 Must Know Facts For Your Next Test

1. The primary immune response is slower than the secondary immune response.
2. It includes both humoral immunity (B cells) and cell-mediated immunity (T cells).
3. Memory cells are produced during the primary immune response for faster future responses.
4. Antibodies produced during this response are mostly IgM.
5. The lag phase, where no antibodies are detectable, usually lasts about 4-7 days.

Review Questions

• What type of antibody is predominantly produced during the primary immune response?
• How long does the lag phase of the primary immune response typically last?
• What types of immune cells are activated during the primary immune response?

Related terms

Secondary Immune Response: A faster and more robust reaction upon subsequent exposure to an antigen due to memory cells.

Humoral Immunity: A component of adaptive immunity mediated by B cells that produce antibodies targeting extracellular pathogens.

Cell-Mediated Immunity: A component of adaptive immunity involving T cells that target infected or abnormal body cells.