Primary vs Secondary Immune Response Explorer
Low Medium High Day 0 Day 10 Day 20 Day 30 Day 40 Day 50 Days since first exposure Antibody titre Protective threshold M M M Memory cells formed IgG IgM Secondary IgG 1st exposure 2nd exposure
Drag to trace the immune response over time Day 0
Day 0 Day 10 Day 20 Day 30 Day 40 Day 50
Response phasePre-exposure
Dominant antibodyNone
Memory cellsNot yet formed
Primary response: Drag the slider to see how antibody levels change after first exposure. IgM appears first, followed by IgG. The peak takes 7–14 days. Click Secondary to compare what happens on re-exposure.
Tip: In the secondary response, memory B cells enable a much faster, higher, and longer-lasting IgG response. Press R to reset.