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How Do Vaccines Train Your Immune System?
疫苗如何训练我们的免疫系统？
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Vaccines introduce harmless versions of germs—or just key parts of them—so your body can practice fighting without getting sick.
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Your immune system responds by producing specialized white blood cells called B cells and T cells that recognize the invader’s unique markers.
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Some of those cells become ‘memory cells,’ which remain in your body for years or even decades after vaccination.
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If the real pathogen later enters your body, memory cells activate much faster and stronger than during the first encounter.
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This rapid response usually stops infection before symptoms develop—or makes illness far milder and shorter.
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mRNA vaccines, like those used for COVID-19, deliver genetic instructions so your own cells temporarily make a harmless viral protein.
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Your immune system then learns to target that protein, just as it would during a real infection.
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Booster shots refresh memory cell numbers and improve protection, especially as immunity naturally fades over time.
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Vaccines don’t overload your immune system—your body deals with thousands of foreign molecules every day from food and air.
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Herd immunity emerges when enough people are protected, making it harder for diseases to spread and shielding those who can’t be vaccinated.