研究：变异新冠病毒在美国迅速传播

最新研究表明，在英国发现的新冠病毒变异株或将在3月成为在美国传播的新冠病毒主流。美国专家称，尽管美国新冠肺炎确诊病例数在近期有所下降，但由于变异新冠病毒的蔓延，美国疫情仍不乐观，民众不可放松警惕。

The coronavirus variant that has moved through the UK is now spreading "rapidly" through the US, according to a new study published on Sunday.

根据2月7日发表的一项新研究，已经在英国传播的变异新冠病毒正在美国“迅速”传播。

The more contagious strain is nearly doubling its prevalence among confirmed cases in the US every nine days.

变异新冠病毒在美国的传播率每隔9天就增长近1倍。

The spread of the variant, known as B.1.1.7, has put added pressure on vaccination efforts worldwide.

这种被称为B.1.1.7的变异新冠病毒的传播给全世界的疫苗接种工作增加了压力。

The US Centers for Disease Control and Prevention (CDC) has predicted it could be the predominant strain by March.

美国疾病控制与预防中心预测，这种变异新冠病毒或将在3月成为在美国传播的新冠病毒的主流。

The report, posted on the preprint server MedRxiv, is a collaboration of several researchers and scientists. It has not yet been peer-reviewed or published in a journal.

这份发布在预印本平台MedRxiv上的报告是几位研究人员和科学家的合作成果，尚未经过同行评审或发表在期刊上。

Case numbers of the new variant are still somewhat small in the US.

在美国，这种变异新冠病毒的病例数仍然很少。

According to the CDC, Florida leads the country in reported cases of B.1.1.7 with 187 as of Thursday, followed by California with 145.

根据美国疾病控制与预防中心的数据，截至2月4日，佛罗里达州报告的B.1.1.7型变异病毒确诊病例为187例，居全美之首，其次是加利福尼亚州，为145例。

"Our study shows that the US is on a similar trajectory as other countries where B.1.1.7 rapidly became the dominant SARS-CoV-2 variant, requiring immediate and decisive action to minimize Covid-19 morbidity and mortality," the report's authors wrote.

该报告的作者写道：“我们的研究表明，美国正处于与其他国家类似的轨迹上，B.1.1.7迅速成为新冠病毒的主要变种，需要立即和果断地采取行动，尽可能地降低其发病率和死亡率。”

trajectory[trəˈdʒektəri]：n.轨道，轨线

This new strain is 35-45% more transmissible than other strains of the virus currently in the US, the report found.

报告发现，这种变异病毒的传染性比目前美国的其他毒株高35-45%。

When the CDC first warned of the new variant's presence in the US in mid-January, it was present in less than 0.5% of cases. By the end of the month, this figure had jumped to 3.6%, according to the study.

美国疾病控制与预防中心1月中旬首次警告美国出现这种变异病毒时，其病例数只占不到0.5%。这项研究发现，到1月底，感染该变异病毒的病例占比上升至3.6%。

The report comes as the United States' winter virus surge passes its peak. Daily cases throughout the country have been falling for about a month, since early January. But the average daily death toll remains extremely high - some 3,000 per day - and hospitals remain under immense pressure.

该报告出炉之际，美国冬季新冠肺炎病例激增的高峰已经过去。自1月初以来，全美各地的每日新增病例数已经下降了约一个月。但是日均死亡人数仍然非常高，大约每天3000人，医院仍然承受着巨大的压力。

The B.1.1.7 variant, first discovered in Britain, has so far spread to more than 50 countries.

B.1.1.7变异病毒首先在英国发现，目前已传播到50多个国家。

As with the original virus, the risk is highest for the elderly and for those with significant underlying health conditions.

与早先的病毒一样，老年人和那些身体健康状况不佳的人风险最高。

There has been some suggestion that the strain may be associated with a 30% higher risk of death, but the evidence on this is not strong, and the data is still uncertain.

有建议认为，这种病毒毒株可能引发死亡风险增加30%，但这方面的证据并不充分，数据仍不确定。

Current vaccines were designed around earlier variants but initial studies have indicated that the Pfizer, Oxford-AstraZeneca and Moderna vaccines will all protect against the B.1.1.7 strain.

目前的疫苗是围绕较早的变种设计的，但初步研究表明，辉瑞、牛津-阿斯利康和摩德纳的疫苗都将对B.1.1.7毒株产生保护作用。