The immune system normally jumps into action in response to bacteria and viruses, deploying antibodies, other molecules and various white blood cells to recognize and destroy trespassers.

• 在正常状况下，免疫系统会对入侵的细菌和病毒采取行动，派遣出能辨识它们的抗体、各式免疫分子以及白血球，将入侵者歼灭。