为什么接种疫苗能预防疾病?当细菌或病毒侵入人体时,身体就会产生一种抵抗这种细菌或病毒的物质,这种物质叫做抗体。针对不同的细菌或病毒会产生不同的抗体,又被称为特异性抗体。病愈后,这种特异性抗体仍然存留在体内,如再有相应的细菌或病毒侵入体内,这种特异性抗体就能保护身体不受这些细菌或病毒的伤害。预防接种就是人为地将经过减毒或灭活等工艺处理的少量细菌或病毒及其代谢产物接种给人,使 Why Vaccination Prevents Diseases? When bacteria or viruses invade the body, the body produces a substance that is resistant to the bacteria or virus called an antibody. For different bacteria or viruses will produce different antibodies, also known as specific antibodies. After recovery, the specific antibodies still remain in the body, such as the corresponding bacteria or viruses invade the body, this specific antibodies can protect the body from these bacteria or viruses. Vaccination is artificially inoculated with a small amount of bacteria or viruses and their metabolites that have been treated through processes such as attenuation or inactivation