学术分享

什么是病毒突变株？

病毒在进行复制时，其遗传物质会发生变化，这些变化被称为“突变”。而具有一个或多个新突变的病毒被称为原始病毒的“变体”（即突变株）。新冠病毒作为一种分子稳定性相对较差的RNA病毒，发生突变是再正常不过的一件事情，目前全球已经发现了数百种新冠病毒的变体，其中大部分对新冠病毒的属性影响很小甚至无影响，我们真正需要关注的是那些会影响病毒属性的突变株。

新冠病毒的“有效”突变株主要从两方面来影响病毒的属性：

1）增强新冠病毒与宿主蛋白ACE2受体的亲和力，从而增强病毒的感染能力；

2）帮助新冠病毒逃逸宿主免疫系统的攻击，导致人类二次感染概率升高甚至降低疫苗有效性。

目前，尚无证据表明已知的突变点会增强新冠病毒的致病性（人感染后病情加重）。

五种重要的突变株

莫慌！核酸检测依然靠谱

新型冠状病毒肺炎疫情爆发以来，新冠病毒核酸检测已经成为群众日常生活中司空见惯的场景，甚至在2021年的春节，一张核酸检测阴性报告成为了大家回乡的“车票”。当下，越来越多新冠病毒突变株的出现引起了人们对于新冠核酸检测有效性的担忧。莫慌，笔者这就给大家排解焦虑~

依据国家新冠诊疗方案的要求，国内主流的新冠检测试剂靶标多为ORF1ab基因和N基因，而目前发现的新冠突变株的“有效”突变点基本集中在S蛋白上，对于检测的有效性不会造成显著影响。此外，伯杰医疗目前亦已完成对现有试剂引物探针与突变株的核对，结果证实：伯杰医疗已经上市的新型冠状病毒2019-nCoV核酸检测试剂盒（荧光PCR法），针对最新突变株均不会出现脱靶和漏检，仍可保证检测试剂的准确性和灵敏性。

如何快速鉴别新冠突变株？

截至目前，全球已知的新冠病毒变体高达数百种，其中引人关注的B.1.1.7突变株、B.1.351突变株和P.1突变株存在的免疫逃逸现象已经引起广泛关注和讨论，隐患依然存在。因而，世卫组织及国际专家依然在密切监测新冠病毒的变化，以便能及时发现重大突变，国内也仍需投入巨大的精力监测新冠突变株的流行情况。看来，对于这些突变株，不该省的工序还是不能省~

当下，全球对新冠突变株（尤其是未知突变株）的监测，主要依赖基因测序技术以及全球科研人员对测序结果数据的共享。但基因测序的时间往往较长，在情况紧急时，及时响应成了一个大问题。因而，对于已知有特异性突变点的突变株，我们也可以通过荧光PCR技术对突变株进行快速鉴别分型和溯源监测，避免贻误疫情防控。

参考文献

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