Your immune system guards you in three layers. First come barriers that keep germs out. Next is a fast innate response that attacks anything foreign. Last is a slower adaptive response that learns one enemy and remembers it. Click each line.
The layered defense
A germ has to get past each wall in turn. Watch which cells and parts are on duty.
Pick a line of defense.
Pick a linebarriers · innate · adaptive
What it does
Active vs passive immunity:active means your body makes its own antibodies, from an infection or a vaccine. It is slow to build but lasts a long time. Passive means you are handed ready-made antibodies, from mom across the placenta or from a shot. That protection is instant but temporary.