疫苗接种，为何不打屁股上？原因是...
最近新冠疫苗接种大热
也成了大家“秀身材”的地方
成千上万的人卷起袖子
接种新冠疫苗
但疫苗为何打在胳膊
而不是屁股上？
01
#疫苗为何打在胳膊而不是屁股上#冲上热搜，引发网友热烈讨论。
有网友一直以为打胳膊是因为脱裤子不方便......
还有网友觉得是出于时间成本考虑：打屁股实在太慢了
有的网友怕疼，觉得疫苗打屁股上躺着睡不着......
还有很多网友想起了小时候，在屁股上打针的场面：“酒精棉花一擦，屁股凉凉的，心也凉凉的”。
02
据参考消息，美国《大众科学》月刊网站5月24日发表利比·理查兹的文章，题为《为什么我们在胳膊而不是臀部注射疫苗》。
Why haven’t they rolled up their pants legs instead? Why do we get most shots in our arms?
文章解释了在胳膊上注射大多数疫苗背后的科学道理：
文章指出，大部分疫苗是注射在肌肉里的，而有些疫苗比如轮状病毒疫苗是口服的，还有些疫苗是皮下注射，比如麻疹、腮腺炎和风疹疫苗。
It’s worth noting that most, but not all, vaccines are given in the muscle – this is known as an intramuscular injection. Some vaccines, like the rotavirus vaccine, are given orally. Others are given just beneath the skin, or subcutaneously – think of the measles, mumps and rubella vaccine. However, many others are given in the muscle.
肌肉之所以成为理想的疫苗接种部位，是因为肌肉组织含有重要的免疫细胞。这些免疫细胞能识别抗原——刺激免疫应答的疫苗所包含的病毒或细菌小片。
Muscles make an excellent vaccine administration site because muscle tissue contains important immune cells. These immune cells recognize the antigen, a tiny piece of a virus or bacteria introduced by the vaccine that stimulates an immune response.
肌肉中的免疫细胞一旦识别出疫苗，就会将抗原传给淋巴管，再由淋巴管将携带抗原的免疫细胞传递给淋巴结。淋巴结是我们免疫系统的重要组成部分，包含更多免疫细胞，可识别疫苗中的抗原，然后再开始制造抗体的免疫过程。
The immune cells in the muscle tissue pick up these antigens and present them to the lymph nodes. Injecting the vaccine into muscle tissue keeps the vaccine localized, allowing immune cells to sound the alarm to other immune cells and get to work.
不过，另一个决定疫苗接种部位的因素是肌肉的体积。成年人和三岁以上的儿童往往是在上臂的三角肌部位接种疫苗。三岁以下的幼儿则在臀部注射疫苗，因为他们的胳膊肌肉比较小，尚未发育好。
Yet another deciding factor in vaccine administration location is the size of the muscle. Adults and children ages three and older tend to receive vaccines in their upper arm in the deltoid. Younger children receive their vaccines mid-thigh because their arm muscles are smaller and less developed.
疫苗接种的另一个考虑因素是便捷性和患者接受度。你能想象在大规模接种疫苗场所脱下裤子的感受吗？卷起袖子更方便，也更容易被接受。
03
现在接种疫苗的方法越来越多
流程也越来越便捷！
还没接种的朋友们抓紧啦～
素材来源：微博、大众科学，侵删。