双语外刊：关于德尔塔变种病毒，科学家们知道些什么？
关于德尔塔变种病毒，科学家们知道些什么？
The Delta Variant: What Scientists Know
The spread of the super-contagious Delta variant has prompted new restrictions around the world and spurred stark new warnings from public health officials.
传染性超强的德尔塔(Delta)变种病毒的传播，促使世界各地采取了新的限制措施，公共卫生官员也发出了新的警告。
“The Delta variant is more aggressive and much more transmissible than previously circulating strains,” Dr. Rochelle P. Walensky, director of the Centers for Disease Control and Prevention, said at a White House briefing last week. “It is one of the most infectious respiratory viruses we know of and that I have seen in my 20-year career.”
“德尔塔变种比以前传播的毒株更具攻击性，也更具传染性，”美国疾病控制与预防中心（Centers for Disease Control and Prevention，简称CDC）主任罗谢尔·P·瓦伦斯基(Rochelle P. Walensky)博士上周在白宫的一个新闻发布会上说，“这是我们所知的、也是我在20年职业生涯中见过的最具传染性的呼吸道病毒之一。”
An internal C.D.C. document, a copy of which was obtained by The New York Times, said that Delta was as transmissible as chickenpox. Although the vaccines continue to provide strong protection against severe disease and death, fully vaccinated people can be infected by, and transmit, Delta, the agency noted. Given these facts, it was time to “acknowledge the war has changed,” the document said.
《纽约时报》获得的一份CDC内部文件的副本中写道，德尔塔变种病毒的传染性与水痘一样强。该机构指出，尽管疫苗继续为预防重症和死亡提供强有力的保护，但完全接种疫苗的人仍可能会被感染并传播德尔塔变种病毒。该文件称，鉴于这些事实，是时候“承认这场战争已经改变了”。
This week, these observations prompted the C.D.C. to change the recommendations it released in May, which had said that fully vaccinated people did not need to wear masks indoors. The agency now says that in virus hot spots, everyone, regardless of vaccination status, should wear masks in indoor public spaces. It also recommended universal masking in schools this fall.
本周，这些观察结果促使CDC改变了它们5月发布的建议，该建议称，接种过疫苗的人不需要在室内佩戴口罩。该机构现在表示，在病毒高发地区，无论是否接种过疫苗，每个人都应在室内公共场所佩戴口罩。它还建议，学校应在今年秋季开学时普遍要求戴口罩。
The World Health Organization, citing the rise of Delta, the dearth of vaccines and high rates of community transmission in many parts of the world, has also encouraged fully vaccinated people to continue wearing masks.
由于德尔塔变种病例攀升、疫苗缺乏以及世界许多地区的社区高传播率，世界卫生组织(World Health Organization)也鼓励完全接种过疫苗的人继续佩戴口罩。
First identified in India, Delta is one of several “variants of concern,” as designated by the C.D.C. and the World Health Organization. It has spread rapidly across the world and poses a particular threat in places where vaccination rates remain low.
德尔塔变种最早是在印度被发现的，是CDC和世卫组织指定的几个“需要注意的变种”之一。它已在世界各地广泛传播，在疫苗接种率仍然较低的地方构成了特别大的威胁。
The variant is now responsible for more than 80 percent of infections in the United States, largely among unvaccinated people, according to the C.D.C. It is already fueling new outbreaks in states with low vaccination rates, including Missouri, Nevada and Arkansas.
根据CDC的数据，目前美国超过80%的感染病例都是由这种变种造成的，被感染的大部分是未接种疫苗的人。它已经在密苏里州、内华达州和阿肯色州等接种率较低的州引发了新的疫情。
Australian cities facing outbreaks of the variant instituted lockdowns, Malaysia extended stay-at-home orders, Ireland delayed plans to reopen indoor dining and Hong Kong restricted incoming flights from Britain, where Delta is widespread. On Thursday, Italy announced that it would begin requiring either proof of vaccination or a recent, negative test in order to dine indoors, visit museums or participate in other activities — a measure prompted, in part, by the Delta variant.
面临该变种暴发的澳大利亚城市已实施封锁，马来西亚延长了居家令，爱尔兰推迟了重新开放室内餐厅的计划，香港则限制了来自英国的入境航班，因为那里的德尔塔变种正在广泛传播。周四，意大利宣布，人们将需要提供接种疫苗或最近核酸检测为阴性的证明，才能在室内用餐、参观博物馆或参加其他活动，这一措施部分是由德尔塔变种促成的。
Roughly 60 percent of American adults have been fully vaccinated, and several widely used vaccines in the United States appear to provide good protection against Delta. But children under 12 are not yet eligible for the vaccine, and vaccination rates have been highly uneven across the country.
约60%的美国成年人已完全接种了疫苗，几种在美国广泛使用的疫苗似乎可以较好地预防德尔塔变种。但是，12岁以下的儿童还不符合接种疫苗的条件，全国各地的接种率也很不均衡。
“If you are not vaccinated, please take the Delta variant seriously,” Dr. Walensky said at the briefing. “This virus has no incentive to let up, and it remains in search of the next vulnerable person to infect. Please consider getting vaccinated and take precautions until you do.”
“如果你还没有接种疫苗，请严肃对待德尔塔变种，”瓦伦斯基博士在新闻发布会上说。“这种病毒并不打算手下留情，它总在寻找下一个易感染的人。请考虑接种疫苗，并在接种前采取预防措施。”
Here are answers to some common questions about the Delta variant.
以下是对德尔塔变种毒株的一些常见问题的回答。
Why are people worried about the Delta variant?
为什么德尔塔变种令人担忧？
Delta, formally known as B.1.617.2, is believed to be the most transmissible variant yet, spreading more easily than both the original version of the virus and the Alpha variant first identified in Britain. It is believed to be roughly twice as contagious as the original virus.
德尔塔变种以前被称为B.1.617.2，被认为是迄今为止传播性最强的变种，比最初的毒株和在英国首次发现的阿尔法(Alpha)变种更易传播。据信，它的传染性大约是原始病毒的两倍。
People who are infected by Delta may carry 1,000 times more virus, and for a longer period of time, than those infected by the original virus.
感染德尔塔变种的人携带的病毒量可能比感染原始病毒的人多1000倍，感染时间也更长。
Other evidence suggests that the variant may be able to partially evade the antibodies made by the immune system after a coronavirus infection or vaccination. And the variant may also render certain monoclonal antibody treatments less effective, the C.D.C. notes.
其他证据表明，该变种可能可以部分躲过冠状病毒感染或接种疫苗后人体产生的抗体。CDC指出，这种变异也可能降低某些单克隆抗体治疗的效果。
Delta is also “likely more severe,” the agency said in its internal document.
该机构在其内部文件中称，德尔塔变种还“可能更严重”。
A recent Scottish study, for instance, found that people infected by the Delta variant were roughly twice as likely to be hospitalized as those infected with Alpha. Studies in Canada and Singapore have turned up similar findings.
例如，苏格兰最近的一项研究发现，感染德尔塔变种的人住院的可能性大约是感染阿尔法变种的两倍。加拿大和新加坡的研究也有类似的发现。
Where is it spreading?
它在哪里传播？
Delta has been reported in 182 countries, and is now the most common variant in many of them, including in India and Britain. Over the past month, infections have nearly doubled in most regions of the world, the W.H.O. said at a news briefing on Friday. “Much of this increase is being driven by the highly transmissible Delta variant,” Dr. Tedros Adhanom Ghebreyesus, the director general of the agency, said at the briefing.
已有182个国家报告了德尔塔变种毒株，它现在在许多国家是最常见的变种，包括印度和英国。世卫组织在周五的新闻发布会上表示，过去一个月里，世界上大多数地区的感染数几乎翻了一番。该机构总干事谭德塞(Tedros Adhanom Ghebreyesus)博士在新闻发布会上说，“这种增长在很大程度上是由高传染性的德尔塔变种推动的。”
Delta was first identified in the United States in March. It spread quickly. In early April, Delta represented just 0.1 percent of cases in the United States, according to the C.D.C. By early May, the variant accounted for 1.3 percent of cases, and by early June, that figure had jumped to 9.5 percent. The C.D.C. now estimates that the number has hit 82.2 percent.
德尔塔变种于今年3月在美国首次发现。它的传播速度很快。CDC的数据显示，4月初，德尔塔变种只占美国病例的0.1%。5月初，该变种占病例的1.3%，到了6月初，这一数字跃升至9.5%。CDC现在估计这个数字已经达到82.2%。
Does the Delta variant cause different symptoms?
德尔塔变种会导致不同的症状吗？
It’s not clear yet. “We’re hurting for good data,” said Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, in June.
目前还不清楚。“我们迫切需要可靠的数据，”明尼苏达大学(University of Minnesota)传染病研究与政策中心主任迈克尔·奥斯特霍尔姆(Michael Osterholm)博士于6月说。
In Britain, where the variant is widespread, reports have emerged that Delta may cause different symptoms than other variants do. Researchers conducting the Covid Symptom Study, which asks people with the disease to report their symptoms in an app, have said that the most common symptoms of Covid have changed as the variant has spread through Britain.
在这种变种广泛存在的英国，报告显示德尔塔变种可能会引起不同于其他变种的症状。冠状病毒症状研究项目的工作人员要求患者在一款应用程序中报告自己的症状。研究人员表示，随着新冠病毒的变种在英国蔓延，最常见的症状已经发生了变化。
“What we’ve noticed is the last month, we’re seeing different sets of symptoms than we were seeing in January,” Tim Spector, a genetic epidemiologist at King’s College London who leads the study, said in June.
“我们注意到，上个月我们看到了与1月份不同的一系列症状，”领导这项研究的伦敦国王学院(King’s College London)的遗传流行病学家蒂姆·斯佩克特(Tim Spector)说。
Headaches, a sore throat and a runny nose are now among the most frequently reported symptoms, Dr. Spector said, with fever, cough and loss of smell less common.
斯佩克特说，头痛、喉咙痛和流鼻涕是目前报告的最常见症状，发烧、咳嗽和嗅觉丧失不太常见。
These data, however, have not yet been published in a scientific journal, and some scientists remain unconvinced that the symptom profile has truly changed. The severity of Covid-19, regardless of the variant, can vary wildly from one person to another.
然而，这些数据还没有在科学杂志上发表，一些科学家仍然不相信症状确实发生了变化。无论冠状病毒的变种如何，其严重程度可能因人而异。
“I’ll wait for published data before I make a conclusion,” Angela Rasmussen, a virologist at the Vaccine and Infectious Disease Organization at the University of Saskatchewan, said last month. “The fact is Covid is generally associated with a wide variety of symptoms, so it’s hard to say if this is truly unusual or if this is anecdotal.”
“在得出结论之前，我会等待公布的数据，”萨斯喀彻温大学(University of Saskatchewan)疫苗和传染病组织(Vaccine and Infectious Disease Organization)的病毒学家安吉拉·拉斯穆森(Angela Rasmussen)上月说。“事实是，冠状病毒通常与各种各样的症状有关，所以很难说这是真的不寻常，抑或只是传闻。”
Even if the data hold up, it does not necessarily mean that Delta itself causes different symptoms than other variants do. A milder symptom profile could be a result of the fact that the variant is primarily infecting younger people, who are the least likely to be vaccinated, or those who may already have some immunity to the virus from a previous infection, for example.
即使数据站得住脚，也不一定意味着德尔塔变种本身引起的症状与其他变种不同。例如，较温和的症状可能是因为，该变种主要感染的是最不可能接种疫苗的年轻人，或那些可能已经对以前感染的病毒有一定免疫力的人。
If I’m vaccinated, do I need to worry about getting sick?
如果我已经接种了疫苗，我需要担心被感染吗？
Although there is not yet good data on how all of the vaccines hold up against Delta, two doses of several widely used shots, including those made by Pfizer-BioNTech, Moderna and AstraZeneca, appear to retain most of their effectiveness against the Delta variant, research suggests.
研究表明，尽管尚未有关于所有疫苗如何对抗德尔塔变种的良好数据，但接种两剂包括辉瑞(Pfizer)-BioNTech、莫德纳(Moderna)和阿斯利康(AstraZeneca)生产的疫苗在内的几种广泛使用的疫苗似乎很大程度上保留了对抗德尔塔变种的有效性。
Delta may cause more frequent breakthrough infections, or infections in people who have been fully vaccinated, than other variants. However, these infections tend to be mild or asymptomatic. The vaccines prevent more than 90 percent of severe disease, the C.D.C. document notes.
与其他变种毒株相比，德尔塔变种可能会导致更频繁的“突破性感染”，即在已经完全接种疫苗的人群中感染。然而，这些感染往往是轻微的或无症状的。CDC的文件指出，疫苗可以预防90%以上的重症情况。
“Being fully vaccinated gives you a high degree of protection against infection, and an even higher degree of protection against severe illness, hospitalization and death,” Dr. Walensky said at last week’s briefing. “That is what these vaccines were designed for.”
“全面接种疫苗可以给你高度的保护，以防感染，而在避免重症、住院和死亡上，效力更高，”瓦伦斯基博士在上周的新闻发布会上说。“这就是这些疫苗的目的。”
According to one recent study, the Pfizer-BioNTech vaccine was 88 percent effective at protecting against symptomatic disease caused by Delta, nearly matching its 93 percent effectiveness against the Alpha variant and 95 percent against the original version of the virus. But a single dose of the vaccine was just 33 percent effective against Delta, the study found.
根据最近的一项研究，辉瑞-BioNTech疫苗在预防德尔塔变种引起的症状性疾病方面的有效性为88%，几乎与其对阿尔法变种和新冠原病毒的93%和95%的有效性相当。但研究也发现，仅接种一针疫苗对德尔塔变种的保护率只有33%。
“Fully immunized individuals should do well with this new phase of the epidemic,” Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, said in an interview last month. “However, the protection offered by a single dose appears low, and of course if you are not at all vaccinated, consider yourself at high risk.”
“在疫情的这个新阶段，完全接种获得免疫的人应该能很好应对，”贝勒大学医学院国家热带医学院(National School of Tropical Medicine at Baylor College of Medicine)的院长彼得·霍特兹(Peter Hotez)博士在上月的一次采访中说。“然而，接种一针疫苗所提供的保护似乎很低，当然如果你一针都没有接种的话，那你就要认为自己处于高风险之中。”
Data on Johnson & Johnson’s single-shot vaccine have been more limited and mixed. Earlier this month, the company reported the results of a small study indicating that its vaccine retained most of its effectiveness against Delta.
强生(Johnson & Johnson)单针疫苗的数据更有限、更参差不齐。本月早些时候，该公司报告了一项小型研究的结果，表明其疫苗对德尔塔变种保持了大部分的有效性。
But a recent study posted online, which has not yet been peer-reviewed, suggested that the company’s vaccine may be much less potent against Delta than against the original strain of the virus. Boosters may ultimately be needed, the study’s authors said.
但最近在网上发布的一项尚未经过同行评审的研究表明，该公司的疫苗对德尔塔变种的效力可能远不如对原始病毒株有效。该研究的作者说，最终可能需要加强针。
American health officials have said that boosters are not recommended at this time but are increasingly acknowledging that people over 65 and those with compromised immune systems may ultimately need another shot, even if they received the Pfizer or Moderna vaccines.
美国卫生官员表示，目前不建议注射加强针，但他们也逐渐承认，65岁以上和免疫系统受损的人最终可能需要再打一针疫苗，即使他们已经接种了辉瑞或莫德纳疫苗。
If I’m vaccinated, can I transmit Delta to others?
如果我已接种疫苗，我还会把德尔塔变种传染给其他人吗？
The C.D.C. believes it’s possible. Although vaccinated people are less likely to become infected by Delta than those who are unvaccinated, those who do contract the virus may carry just as much of the virus in their noses and throats as unvaccinated people, Dr. Walensky said this week.
CDC认为这是可能的。瓦伦斯基博士本周表示，尽管已接种疫苗的人比未接种疫苗的人更不易感染德尔塔变种，但那些感染病毒的人鼻子和喉咙中携带的病毒可能与未接种疫苗者一样多。
“Delta variant vaccine breakthrough cases may be as transmissible as unvaccinated cases,” the internal C.D.C. document said.
“德尔塔变种疫苗突破病例的传染性可能与未接种疫苗的病例一样，”CDC的内部文件称。
A new C.D.C. study, published on Friday, documented a Covid-19 outbreak among people who attended summer events or large public gatherings in Barnstable County, Ma. Among the 469 cases identified among Massachusetts residents, 74 percent occurred in people who had been fully vaccinated. (Nearly all of the infections were caused by the Delta variant, sequencing suggests.) On average, they carried roughly the same amount of virus as unvaccinated people, researchers found.
CDC周五发表的一项新研究记录了在马萨诸塞州巴恩斯特布尔县参加夏季活动或大型公共集会的人群中暴发的新冠疫情。在马萨诸塞州确诊的这469例病例里，74%发生在已经完全接种疫苗的人群中。（测序显示，几乎所有的感染都是由德尔塔变种引起的。）研究人员发现，平均而言，他们携带的病毒数量与未接种疫苗的人大致相同。
Will Delta return us to last year’s pandemic peak?
德尔塔变种会让我们回到去年的疫情高峰吗？
After a long and steady decline, cases are on the rise again in the United States, likely fueled by Delta. Roughly 71,000 new infections are reported each day, up from about 11,000 a day a little over a month ago.
在经历了长期稳定的下降之后，美国的病例数再次上升，可能是受德尔塔变种的推动。每天报告的新感染病例从一个多月前的约1.1万例上升到了约7.1万例。
But case numbers remain far below last winter’s peak, and experts do not expect them to rise that high again. “I think we are not going to see another big, national surge in the United States, because we have enough vaccination to prevent that,” Dr. Osterholm said last month.
但病例数量仍远低于去年冬天的峰值，专家预计不会再上升到那样高的水平。上月，奥斯特霍姆说：“我认为我们不会看到美国再出现一次全国性的大暴发，因为我们有足够的疫苗来预防这种情况。”
However, Delta is driving outbreaks in areas where vaccination rates are low.
然而，德尔塔变种正在疫苗接种率低的地区引发疫情。
“In places where there’s still a lot of susceptibility to the virus, it opens a window for cases to start going up again,” Justin Lessler, an infectious disease epidemiologist at the University of North Carolina, said in June. “But even in those states, and certainly nationally, we’re probably not getting back to the numbers we were seeing last winter.”
“在那些仍然很容易感染病毒的地方，它为病例再次上升打开了一扇窗，”6月，约翰·霍普金斯大学(Johns Hopkins University)传染病流行病学家贾斯汀·莱斯勒(Justin Lessler)说。“但在那些州，当然也包括全国范围内，我们可能不会回到去年冬天看到的那种数字。”
And because many of the most vulnerable Americans — including older adults and those with chronic health conditions — have been vaccinated, hospitalization rates are increasing more slowly than the number of total infections.
由于许多最脆弱的美国人——包括老年人和患有慢性疾病的人——已经接种了疫苗，住院率的增长比总感染人数的增长要慢。
What can I do?
我能做什么？
Get vaccinated. If you’re already vaccinated, encourage your family, friends and neighbors to get vaccinated.
接种疫苗。如果你已经接种，鼓励你的家人、朋友和邻居去接种。
Vaccination is likely to slow the spread of all the variants and reduce the odds that new, even more dangerous variants emerge.
接种疫苗有可能减缓所有变异的传播，并减少新的甚至更危险的变种出现几率。
“I encourage people who are vaccinated to trust in the vaccines but be cognizant that new variants will continue to occur where transmission exists,” Saskia Popescu, an infectious disease epidemiologist at George Mason University, said last month. “So it’s really about ensuring local, national and global vaccination.”
“我鼓励接种疫苗的人信任疫苗，但要认识到，在存在传播的地方，新的变种将继续出现，”乔治·梅森大学(George Mason University)传染病流行病学家萨斯基娅·波佩斯库(Saskia Popescu)上月说。“所以重点是地方、国家和全球的疫苗接种。”
Face masks, which remain a particularly important tool for those who are ineligible for or do not have access to vaccines, can provide additional protection. The C.D.C. now recommends that even fully vaccinated people wear masks in some circumstances: in public indoor spaces in areas of the country in which cases are surging; if they have compromised immune systems; or if they live with young children, older adults or others who may be especially vulnerable to the virus.
对于那些没有资格或无法获得疫苗的人来说，口罩仍然是一个特别重要的手段，可以提供额外的保护。CDC现在建议，即使已经接种过疫苗的人，在一些情况下也要戴口罩：在病例激增地区的室内公共场所；如果他们的免疫系统受损；或者如果他们与儿童、老年人或其他可能特别容易感染的人生活在一起。
“We are fighting the same virus, but a virus that’s become fitter and better adapted to transmitting among us humans,” Dr. Michael Ryan, executive director of the W.H.O. health emergencies program, said at a news briefing on Friday. “That’s the change. But the way in which we fight the virus hasn’t changed. And vaccines and all of the other measures still remain hugely effective if applied in a comprehensive fair, equitable, and rapid manner.”
“我们正在抗击同一种病毒，但这种病毒已变得更强健、更易于在人类之间传播，”世卫组织卫生紧急项目执行主任迈克尔·瑞安(Michael Ryan)博士在上周五的新闻发布会上说。“这是已经发生改变的。但我们对抗病毒的方式并没有改变。如果以全面、公平、公正和迅速的方式实施，疫苗和所有其他措施仍将非常有效。”
来源：纽约时报
