流感疫苗是如何起作用的?

流感疫苗是如何起作用的?

作者：Harpreet Singh， MD
专业: 家庭医学

每一年, 在291,000到646,000人之间 worldwide die from the flu 和 flu-related respiratory illnesses. 当 accounting for how the flu can cause or exacerbate serious 和 sometimes fatal conditions like cardiovascular disease or diabetes, that number 可能超过一百万.

That’s why fighting the flu is a global issue – 和 getting your 一年ly flu shot is the first 和 best defense.

什么是流感?

While we tend to refer to it generically as “the flu”, it’s 实际上是四个不同的属 列性感冒病毒 然后按菌株进一步划分.

A型流感病毒 is the type we associate with flu p和emics, commonly infecting humans, 其他哺乳动物和鸟类. You may recall outbreaks of H1N1 swine flu 和 H5N1 bird flu; both are strains of 列性感冒病毒一.

B型流感病毒, which can be found in both human 和 seal populations, is a less common 主要影响幼儿的一种. 丙型流感病毒 tends to be milder (similar in severity to a common cold) 和 non-epidemic.

D型流感病毒 can affect some animal populations, but does not affect humans.

为什么我每年都要打一针?

Typically, there are only a few strains of influenza that circulate each 一年. However, viruses like the flu can mutate quickly, which means new strains of the flu virus are constantly evolving.

That’s why, every February, the World Health Organization (WHO) uses advanced modeling 和 population data to assess which strains of the flu have the greatest p和emic potential for the Northern Hemisphere. 制造商 then produce vaccines based on these recommendations ­– which usually protect against 2 strains of A型流感病毒 as well as 1-2 strains B类的. Because the dominant strains change from 一年-to-一年, so must 流感疫苗.

注射流感疫苗会得流感吗?

不，你不会因为注射流感疫苗而得流感. 很不幸，这是 a common misconception that dissuades some from getting their annual 疫苗接种.

Vaccines do contain a viral component that helps your immune system create 抗活性菌株抗体. 然而，病毒的成分 shot is dead, meaning it can’t cause infection, 和 nasal spray vaccines contain a “live attenuated” virus, meaning it’s weakened to the point that it’s unable to replicate in average body heat.

While you cannot get the flu from the flu shot, it is still possible to 接种疫苗后会生病. 常见的原因包括：

• 坏的时间: After being vaccinated, it takes your body about two weeks to build up enough antibodies to fight off the full-fledge flu virus. 在这 window, unfortunately, it’s still possible to get sick with the flu.
• 错误的应变: 每一年, the WHO makes the best possible prediction of what strains 流感将是最普遍的. 正如我们在2017-2018年流感季节看到的那样， 有时这些预测是错误的. 这样的话，即使得了流感 shot, you won’t be immune to the dominant strain.
• 误诊: Because their symptoms are so similar, there’s a good chance that the “flu” a vaccinated person gets is actually just a really 严重的感冒. While it may not make you feel better while sick, the common 感冒远没有流感那么危险.