同时，针对新冠病毒是否变异的研究，也是目前学界的焦点。

　　日前，中国科学团队发现，新冠病毒演化出了两个亚型。

　　The novel coronavirus has evolved into two major subtypes, a Chinese study has revealed.

　　3月3日，中国科学院主办的《国家科学评论》(National Science Review)发表题为《关于SARS-CoV-2的起源和持续进化》的论文。

　　The study, titled On the origin and continuing evolution of SARS-CoV-2, was published on the National Science Review of the Chinese Academy of Sciences (CAS) on Tuesday (March 3).

　　论文通过对目前为止最大规模的103个新冠病毒全基因组分子进化分析，发现病毒株已发生了149个突变点，而且多数是近期产生的。该研究揭示：新冠病毒已经演化出L和S两个亚型。其中101个属于这两个亚型。

　　By analyzing the genome-wide molecular evolution of 103 novel coronavirus samples, scientists found 101 samples that can be categorized into S-cov and L-cov based on 149 mutation spots on virus strains.

　　基因组数据表明，感染S型的比例占30%， L型的感染比例占70%。S型与蝙蝠来源的冠状病毒在进化树上更接近，从而得出S型相对更古老的结论。L型在武汉爆发疫情的早期阶段更为普遍。

　　The paper states that S type, accounting for 30 percent, is closer to the bat-related coronavirus and is relatively older, while the L type was more prevalent in the early stages of the outbreak in Wuhan.

　　人为干预可能对L亚型施加了更大的选择性压力，如果没有这些干预，L亚型可能更具侵略性和扩散得更快速。

　　Human intervention may have placed more severe selective pressure on the L type, which might be more aggressive and spread more quickly than the S type.

　　不过，论文作者也指出研究数据很有限。L型如何从S型演化而来，以及变异如何影响病毒传播和发病机制，依然是未知数。

　　However, the authors highlighted the fact the data examined in the study is very limited. How L type strains evolved from S type, as well as how these mutations would affect the transmission and pathogenesis of the virus, are still unknown.

　　样本显示，大部分患者只感染了L亚型或S亚型中的一个。但其中一位近期有过武汉旅行史的63岁美国患者却很有可能同时感染了L型和S型新冠病毒。不过，该论文作者表示目前还无法排除新突变型的可能性。

　　Scientists also found most patients caught either the L or S type of novel coronavirus strain. But there might be exceptions to the rule that should be followed with further research. For example, the study said a 63-year-old female patient in Chicago had likely contracted both L and S types of novel coronavirus strains when she traveled in Wuhan and returned to the United States on Jan 13.

　　另据新华网报道，巴西研究人员对病毒基因测序的结果显示，巴西两个确诊病例体内的病毒有所不同。巴西阿道弗·卢茨研究所和圣保罗大学医学院的研究人员对这两个病例体内的病毒进行了基因测序，结果发现首个病例体内的病毒与在德国发现的病毒更加相似，而第二个病例体内的病毒则与在英国发现的病毒更加相似。二者与在中国发现的病毒也有所不同。据介绍，这两名患者都是今年2月在意大利感染后回到巴西的。