b-cells

When a virus enters your body, it triggers a response that unfolds in stages over hours, days, and weeks. The innate immune system fires within minutes, buying time while the adaptive immune system — which can generate targeted weapons against any pathogen — prepares a precise counterattack. The two systems do not operate independently: each depends on signals from the other, and the timing of their interaction determines whether the infection is cleared in a week or becomes severe.

Explore how the immune system defends your body — from skin barriers to T cells, vaccines, autoimmunity, and cancer immunotherapy.