Because bacteria are outside of cells and when antibodies bind to them they can neutralize them.

因为细菌生存在细胞外,抗体结合细菌并中和掉它们

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They can't always neutralize viruses because the viruses are predominantly inside cells.

抗体不是总能中和病毒,因为病毒主要在细胞中

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So, either stimulates the production of-- and differentiation of B-cells, to produce a specific antibody that can neutralize the virus, or stimulates the production of cytotoxic T-cells that can kill infected cells within your body.

所以,疫苗的刺激要么能够,促进B淋巴细胞产生和分化,以生成特定的抗体来杀灭病毒,要么刺激T细胞释放细胞毒素,杀死身体里被感染的细胞

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