Omicron BA.2的报道翻译

翻译自：https://www.medicalnewstoday.com/articles/omicron-subvariants-ba-1-vs-ba-2-what-the-latest-data-says

The BA.2 subvariant of Omicron, or the “stealth” variant,has been outcompeting the previously dominant BA.1 subvariant in several countries.
欧米克隆的 BA. 2变种，或者说“隐形”变种，已经在几个国家超过了先前占主导地位的 BA. 1变种。
Recent studies suggest that BA.2 has a competitive advantage over BA.1, mostly due to its increased transmissibility.
最近的研究表明，BA. 2比 BA. 1具有竞争优势，主要是由于它的传递性增加。
The BA.2 variant may also be slightly better at evading immunity than BA.1, which could be contributing to its rapid spread.
与 BA. 1相比，BA. 2变体在逃避免疫方面可能略好一些，这可能是其迅速传播的原因之一。
Although BA.2 is more contagious than BA.1, clinical data do not suggest a significant difference in disease severity.
虽然 BA. 2比 BA. 1更易传染，但临床数据并未显示在疾病严重程度上有显著差异。

All data and statistics are based on publicly available data at the time of publication. Some information may be out of date. Visit our coronavirus hub and follow our live updates page for the most recent information on the COVID-19 pandemic.

所有数据和统计数字均以发表时的公开数据为基础。有些信息可能过时了。访问我们的冠状病毒中心，关注我们的实时更新页面，获取2019冠状病毒疾病流感大流行的最新信息。

The Omicron variant, which researchers first sequenced in South Africa and Botswana in November 2021, was found to be more transmissible but cause less severe disease than its predecessor — the Delta variant.

研究人员于2021年11月在南非和博茨瓦纳首次对 Omicron 变异基因进行测序，发现该变异基因比其前身 Delta 变异基因更具传染性，但导致的疾病不那么严重。

Owing to being more contagious, Omicron rapidly supplanted Delta as the dominant variant worldwide. Currently, it accounts for 99%Trusted Source of all sequenced cases.

由于传染性更强，欧米克隆迅速取代三角洲成为全球主要变种。目前，它占99% 的可信来源的所有测序的情况下。

Moreover, since it emerged, scientists have categorized Omicron’s subvariants or lineages into three groups: BA.1, BA.2, and BA.3.

此外，自从它出现以来，科学家们已经将欧米克隆的亚变种或谱系分为三组: BA. 1、 BA. 2和 BA. 3。

Although the BA.1 subvariant started as the dominant Omicron lineage across the globe, since December 2021, the proportion of COVID-19 cases linked to the BA.2 variant has been rapidly increasing.

尽管 BA. 1亚变异体在全球范围内开始成为占主导地位的 Omicron 血统，但自2021年12月以来，与 BA. 2亚变异体相关的2019冠状病毒疾病病例的比例一直在迅速增加。

This has raised concerns about the severity and transmissibility of BA.2. Here’s what researchers have found so far:

这引起了人们对 BA 的严重性和遗传性的关注。2. 以下是研究人员迄今为止的发现:

Omicron subvariant BA.2 overtakes BA.1

Omicron 亚变体 BA. 2超过 BA. 1

BA.2 has been especially prominent in countries in Southeast Asia, Africa, and Europe. Recent analyses have indicated that it has displaced BA.1 as the dominant Omicron sublineage in Denmark, Singapore, India, South Africa, and Austria. The rapid ascent of BA.2 is illustrated by the increaseTrusted Source in its prevalence from 20% in the last week of December 2021 to 66% by the third week of January 2022 in Denmark.

在东南亚、非洲和欧洲的国家，BA. 2尤其突出。最近的分析表明，在丹麦、新加坡、印度、南非和奥地利，它已经取代 BA. 1成为 Omicron 的主要分支。可信源的增加说明了 BA. 2的快速上升
从2021年12月最后一周的20% 上升到2022年1月第三周的66% 。

The proportion of BA.2 cases in the United States remains low at 3.8% so far, but health experts expect it to rise.

到目前为止，美国 BA. 2病例的比例仍然很低，只有3.8% ，但卫生专家预计这一比例还会上升。

Preprint studies that are yet to be peer reviewed have characterized differences between the BA.1 and BA.2 subvariants, which may explain why the latter is outcompeting its sibling variant.

尚还没有经过同行审查的预印本在研究 BA. 1和 BA. 2亚型之间的特点差异，这可能解释为什么后者是竞争超过其兄弟变异。

Although BA.2 shares many of BA.1’s mutations, the two subvariants differ by 28 mutations, some of which are responsible for the rapid surge in BA.2 cases.

虽然 BA. 2和 BA. 1有许多相同的突变，但是这两个亚变异有28个不同的突变，其中一些是 BA. 2病例迅速增加的原因。

Notably, the mutations unique to these subvariants are also present in the spike protein, which mediates the entry of SARS-CoV-2 into cells and is the target of COVID-19 vaccines. Specifically, BA.2 carries eight new mutations in the spike protein but lacks 13 mutations that the BA.1 spike protein harbors.

值得注意的是，这些亚变异所特有的突变也存在于刺突蛋白中，刺突蛋白介导 sars-cov-2进入细胞，是2019冠状病毒疾病疫苗的目标。具体来说，BA. 2在 spike 蛋白中携带8个新的突变，但缺少 BA. 1 spike 蛋白所携带的13个突变。

BA.2 seems to be more transmissible

BA. 2似乎更具传染性

The rapid surge in the prevalence of BA.2 in multiple countries suggests that this variant is more contagious than BA.1. One study estimates that BA.2 is up to 33% more transmissible than BA.1 and considers that its spread could be a serious issue for global health in the near future.

多个国家 BA. 2流行率的迅速上升表明，这种变异比 BA. 1更具传染性。一项研究估计 BA. 2的传染性比 BA. 1高出33% ，并认为它的传播在不久的将来可能成为全球健康的一个严重问题。

Moreover, a nationwide study comparing the spread of the BA.1 and BA.2 variants in Danish households in late December 2021 and January 2022 suggested that the latter was more contagious. The study found that the secondary attack rate, which measures the probability of transmission of the virus to household members, was 39% for BA.2 and 29% for BA.1.

此外，一项比较2021年12月底和2022年1月丹麦家庭 BA. 1和 BA. 2变异扩散情况的全国性研究表明，后者传染性更强。研究发现，用于衡量病毒传播给家庭成员的可能性的二次攻击率，BA 2为39% ，BA 1为29% 。

The study also reported that fully vaccinatedTrusted Source and booster-vaccinated individuals were less likely to pass on or contract an infection due to either subvariant compared with unvaccinated individuals.

该研究还报告说，完全接种疫苗的可信来源
与未接种疫苗的个体相比，接种疫苗的个体由于这两种亚变异而传播或感染的可能性较小。

In addition, unvaccinated individuals were more likely to spread the BA.2 subvariant to their household members than BA.1.

此外，未接种疫苗的个体比接种疫苗的个体更有可能将 BA. 2亚变异基因传播给其家庭成员。

BA.2 can evade immunity but not completely

BA. 2可以躲过免疫，但不能完全躲过

The household transmission data from the Danish study also showed that both vaccinated and unvaccinated individuals were more susceptible to a SARS-CoV-2 infection due to BA.2 compared with BA.1.

来自丹麦研究的家庭传播数据还表明，接种疫苗和未接种疫苗的个体由于 BA. 2而比 BA. 1更容易受到 sars-cov-2感染。

The relative increase in susceptibility to the BA.2 variant was greater in vaccinated individuals than unvaccinated individuals. In other words, it was more adept at evading the immune protection offered by vaccines to cause an infection.

接种疫苗的个体比未接种疫苗的个体更易感染 BA. 2变异。换句话说，它更善于逃避疫苗提供的免疫保护，从而引起感染。

Speaking to Medical News Today, the co-author of this study, Dr. Frederik Plesner Lyngse, a researcher at Copenhagen University, said, “[BA.2] possesses immune-evasive properties that reduce the protective effect of vaccination against infection, but [does] not increase its infectiousness from vaccinated persons with breakthrough infections.”

哥本哈根大学研究人员弗雷德里克 · 普莱斯纳 · 林格斯博士对《今日医学新闻》说: “[ BA. 2]具有免疫逃避特性，可以降低疫苗对感染的保护作用，但不会增加突破性感染（即已经感染过的）疫苗接种者的传染性。”

“All individuals are more susceptible to BA.2 compared to BA.1, unconditional on their vaccination, previous infection status [or both]. Unvaccinated individuals are more infectious if they [acquire an infection] with BA.2 compared to BA.1, while vaccinated individuals (vaccination and/or previous infection) that have a breakthrough infection are less infectious if [they contract an infection] with BA.2 compared to BA.1.”
– Dr. Frederik Plesner Lyngse

“与 BA. 1相比，所有人都更容易感染 BA. 2，与接种疫苗无关，以前的感染状态[或两者都有]也无关。与 BA. 1相比，未接种疫苗的个体如果感染 BA. 2更具传染性，而接种疫苗的个体(接种疫苗和/或以前感染)感染 BA. 2传染性降低如果他们之前感染过的话”- 弗雷德里克 · 普莱斯纳 · 林斯博士

The levels of antibodies that can bind and neutralize SARS-CoV-2 tend to predictTrusted Source the extent of protection from infection. Two studies have independently shown that individuals immunized with mRNA vaccines showed significantly lower levels of neutralizing antibodies against the BA.1 and BA.2 subvariants than the original wild-type SARS-CoV-2.

结合和中和 sars-cov-2的抗体水平将用于预测可信来源
防止感染的程度。两项独立的研究表明，用信使核糖核酸（mRNA）疫苗免疫的个体明显表现出：对抗 BA. 1和 BA. 2亚型的抗体水平中和性低于原始野生型 SARS-CoV-2。

Receiving a third shot as a booster also increased neutralizing activity against these Omicron lineages, but the neutralizing antibodies levels in response to BA.2 were slightly lower than BA.1.

接受第三次注射作为加强剂也增加了对这些 Omicron 谱系的中和活性，但是对 BA. 2的中和抗体水平略低于 BA. 1。

Dr. Lyngse said they found that “vaccinations work in both reducing susceptibility (probability of [acquiring infection]) and infectiousness (probability of [causing infections in] others) — and that boosters reduce it even more.”

林格斯博士说，他们发现“接种疫苗既能降低易感性(感染的可能性) ，也能降低传染性(在其他人身上引起感染的可能性) ，而且疫苗的支持者还能进一步降低感染率。”

Given the modest difference in neutralizing activity against BA.2 and BA.1, Dr. Dan Barouch, a virologist at Harvard Medical School and author of one of the above studies, noted:

鉴于针对 BA. 2和 BA. 1的中和活性存在一定差异，哈佛医学院病毒学家、上述研究的作者 Dan Barouch 博士指出:

“The ability of BA.2 to outcompete BA.1 is probably due to increased transmissibility of the virus, rather than additional immune escape beyond BA.1.”

BA. 2战胜 BA. 1的能力可能是由于病毒传播能力的增强，而不是比 BA. 1更强的免疫逃逸。

Do treatments work against BA.2?

治疗方法对 BA 有效吗？

Researchers developed the currently available COVID-19 vaccines to elicit an immune response against the wild-type SARS-CoV-2 spike protein. The lower neutralizing antibody response against BA.1 and BA.2 in fully vaccinated individuals likely reflects the high number of mutations in the Omicron spike protein.

研究人员开发了目前可用的2019冠状病毒疾病疫苗，以引发针对野生型 sars-cov-2棘突蛋白的免疫反应。在完全接种的个体中，抗体中和 BA. 1和 BA. 2的反应较低，可能反映了 Omicron spike 蛋白的突变数量较高。

These mutations on the Omicron spike protein also explain why most of the monoclonal antibodies that were effective against previous SARS-CoV-2 variants have diminished neutralizing activity against BA.1.

Omicron 突刺蛋白的这些突变也解释了为什么大多数对以前的 sars-cov-2变异有效的单克隆抗体对 BA 的中和活性降低。

Sotrovimab was one of the few monoclonal antibodies that retained neutralizing activity against this variant.

Sotrovimab 是为数不多的对该变异保持中和活性的单克隆抗体之一。

Recent studies have shown a significant decline in the neutralizing activity of sotrovimab against the BA.2 variant. The AstraZeneca antibody combination Evusheld and the Eli Lily antibody bebtelovimab are two authorized antibodies that still retain activity against both BA.1 and BA.2 variants.

最近的研究表明 sotrovimab 对 BA. 2变异体的中和活性显著下降。阿斯利康抗体组合 Evusheld 和 Eli Lily 抗体 bebtelovimab 是两种经授权的抗体，仍然保持对 BA. 1和 BA. 2变异体的活性。

In light of the ability of these Omicron subvariants to evade most therapeutic monoclonal antibodies, scientists fear that further mutations in the SARS-CoV-2 spike protein could render all currently available monoclonal antibody treatments ineffective.

鉴于这些 Omicron 亚基变异体有能力逃避大多数治疗性单克隆抗体，科学家担心 sars-cov-2棘突蛋白的进一步突变可能使目前所有可用的单克隆抗体治疗无效。

BA.2 does not seem to be more severe

BA. 2似乎没有更严重

A recent laboratory study suggests that a BA.2 infection may cause more severe illness than BA.1. The study showed it replicated much faster than BA.1 in cultures of upper and lower respiratory tract cells.

最近的一项实验室研究表明 BA. 2感染可能比 BA. 1引起更严重的疾病。研究表明，在培养的上、下呼吸道细胞中，它比 BA. 1复制得更快。

Subsequent experiments in hamsters also suggested that BA.2 had a superior ability to replicate and spread in the lungs than BA.1. It also caused more lung damage and had greater adverse effects on lung function in these experiments.

随后在仓鼠身上的实验也表明 BA. 2在肺部复制和传播的能力比 BA. 1更强。在这些实验中，它还造成了更多的肺损伤，对肺功能有更大的不利影响。

However, data on disease severity in humans so far suggest that the BA.2 variant does not cause more severe illness than BA.1.

然而，迄今为止关于人类疾病严重程度的数据表明，BA. 2变异并不比 BA. 1引起更严重的疾病。

A study that researchers conducted in South Africa evaluated the risk of hospitalization due to BA.1 and BA.2 infections between December 5, 2021, and January 29, 2022, when the prevalence of BA.2 infections in the country grew from 3% to 80%. Upon analyzing the outcome of 95,470 COVID-19 cases, the study found that a similar proportion of individuals with BA.1 and BA.2 infections required hospitalization.

研究人员在南非进行的一项研究评估了2021年12月5日至2022年1月29日期间 BA. 1和 BA. 2感染住院的风险，当时该国 BA. 2感染的流行率从3% 上升到80% 。通过分析95,470例2019冠状病毒疾病感染病例的结果，研究发现类似比例的 BA. 1和 BA. 2感染者需要住院治疗。

A statementTrusted Source by the World Health Organization (WHO), citing this study and other unpublished real-world evidence from the United Kingdom and Denmark, noted that BA.2 variant may not differ from BA.1 in its ability to cause severe illness in humans.

世界卫生组织(世卫组织)的一份声明援引这项研究和其他来自英国和丹麦的未发表的现实世界证据，指出 BA. 2变体在引起人类严重疾病的能力上可能与 BA. 1变体没有区别。

The discrepancy between the laboratory study and real-world clinical data could be due to the inability of the animal model to recapitulate all aspects of COVID-19 in humans.

实验室研究和现实临床数据之间的差异可能是由于动物模型无法再现人体内2019冠状病毒疾病的所有方面。

Dr. Larry Corey, a virologist at Fred Hutchinson Cancer Research Center in Seattle, said, “Currently, there is no evidence either from South Africa or places in the U.S. that suggest differences in the clinical spectrum and course between BA.1 and BA. 2.”

西雅图福瑞德哈金森肿瘤研究中心的病毒学家 Larry Corey 博士说: “目前，无论是南非还是美国，都没有证据表明 BA. 1和 BA. 1之间的临床谱和病程存在差异。2.”

“The BA.2 epidemic has had a 6–8-week later start, so severity data do lag behind. But to date, there is no evidence of significant differences, and cross-protection between the two variants seems in the short term quite high,” he told MNT.

“ BA. 2疫情开始的时间晚了6-8周，因此严重程度数据确实滞后。但是到目前为止，没有证据表明这两种变异有显著差异，而且两种变异之间的交叉保护在短期内似乎相当高。