active immunity

Active immunity occurs when your body's immune system produces its own defenses against a pathogen. This happens naturally if you're exposed to a disease and your body responds by making antibodies and memory cells, which provide protection if you're exposed again. It can also be achieved through vaccines, which introduce a safe part of a virus or bacteria to train your immune system without causing illness. This process usually takes some time to develop but offers long-lasting protection, helping your body recognize and fight the real infection more effectively in the future.