"Active immunity"指的是身体对某种疾病的免疫反应，通常是通过接种疫苗或接受免疫接种而产生的。这种免疫反应通常会在接种疫苗后的一段时间内产生抗体，从而保护身体免受疾病的侵害。
以下是一篇关于active immunity的英文范文：
The importance of active immunity
Active immunity is a crucial component of protecting ourselves from diseases. Through vaccination, we can generate an immune response that produces antibodies that protect us from diseases such as influenza, measles, and polio. Vaccinations are a safe and effective way to protect ourselves and our families from these diseases, and they are a crucial part of maintaining a healthy and safe community.
However, active immunity is not the only way to protect ourselves from diseases. We can also rely on natural immunity, which occurs when we are exposed to the disease through infection. Although natural immunity is not as strong as active immunity, it can still provide some protection against diseases.
In conclusion, active immunity is an essential component of protecting ourselves from diseases. Vaccinations are a safe and effective way to generate an immune response that protects us from diseases, and they are crucial for maintaining a healthy and safe community.
active immunity的意思是主动免疫。
在英文范文中的相关使用，可以参考以下示例：
通过注射疫苗，实现了对疾病的active immunity，即对相关疾病的主动免疫。 人体在感染病毒后可获得对该病毒的active immunity，即获得该病毒的免疫能力。
“active immunity”在英文中通常指身体对病原体接触后，病原体刺激身体产生的可以对抗相同病原体的免疫力。
例如在医学上，它通常指的是身体接触病原体后，病原体刺激身体产生的可以对抗相同病原体的能力。这种免疫能力一般可以维持一段时间，之后可能会消失，也可能会增强，形成长期免疫力。
近年来，“active immunity”这一词的使用频率有所下降，可能更多的是用“passive immunity”来描述被动免疫的概念。以上信息仅供参考，建议通过专业网站、书籍等渠道获取更多信息。