They acquire immunity naturally just like our bodies acquire immunity when we get a cold.

它们通过自然途径了免疫，就像我们在感冒之后可以免疫一样。

There are two ways in which humans acquire natural immunity.

人类自然免疫的方式有两种。

A lower than expected mortality among the elderly may have been explained by acquired immunity.

老年人的死亡率低于预期可能是由于免疫所致。

Another series of letters from an American private provides a good example of acquired immunity.

另一组来自美国士兵的信件是“取免疫”的一个很好的例子。

Now, artificially acquired immunity can help the body to fight disease, so we can use active immunization as a preventative measure.

现在，人工免疫可以帮助身体对抗疾病，所以我们可以采用主动免疫作为预防措施。

If you've been infected with one of the previous variants, how well does that immunity, that infection acquired immunity, protect you against this.

如果你已经感染了之前的一种变异病毒，那么因感染的免疫，是否能有效保护人们免受奥密克戎感染呢？

There is strong evidence suggesting that exposure to previous waves of the Spanish flu could generate acquired immunity in those who had been infected, but had survived.

有强有的证据表明，接触过之前几波西班牙流感的人可能会产生“免疫”，所以他们幸存了下来。

He was intrigued by stories that people, typically milkmaids, who had contracted a mild infection, cowpox, from their cows, had acquired an immunity to the much deadlier smallpox, and wondered whether cowpox could provide a safer method of inoculation.

他对这样的故事产生了浓厚兴趣：通常是挤奶女工，她们从牛身上感染了轻微的牛痘病毒后，竟然了对更为致命的天花的免疫。这让他考，牛痘是否能提供一种更安全的接种方法。