← Chapter 13
Microbiology · Chapter 13
Primary vs Secondary Response
The first time the body meets an antigen it answers
slowly
and modestly. The next time, it
remembers
— responding faster and far more strongly. Drag the slider across the timeline to watch the antibody titer rise, fall, and surge on re-exposure.
Antibody titer over time
Day
0
of 180
First exposure
The two responses
drag the slider to begin
Feature
Primary
1st exposure
Secondary
re-exposure
Lag time
5–10 days
1–3 days
Onset speed
Slow
Rapid
Peak titer
Lower
10–100× higher
Main antibody
IgM → IgG
IgG (high affinity)