新冠肺炎疫情是否會(huì)在晚些時(shí)候迎來第二波？人類又該如何阻止其暴發(fā)？美國媒體最近針對(duì)這些人們關(guān)心的問題進(jìn)行了解讀。

As authorities the world over consider when to lift economy-crippling movement restrictions aimed at curbing coronavirus infections, the fear on everyone’s minds can be expressed in two words: second wave. The concern is that, once quelled, the pandemic will resurface with renewed strength, causing a repeat of rising infections, swamped health systems and the necessity of lockdowns.

旨在遏制新冠病毒感染的出行限制措施對(duì)經(jīng)濟(jì)造成了損害。當(dāng)世界各地政府考慮何時(shí)取消這些限制措施時(shí)，每個(gè)人心中的恐懼可以用三個(gè)字表達(dá)：第二波。大家擔(dān)心的是，暫時(shí)平息之后，疫情將以新的強(qiáng)度卷土重來，再次導(dǎo)致感染病例增加、衛(wèi)生系統(tǒng)癱瘓以及必須實(shí)施封鎖。

quell [kwel]: vt.平息；鎮(zhèn)壓；減輕；消除

1.What’s a second wave?

什么是第二波？

Pandemics are caused by new pathogens that the vast majority of humans have no immune protection against. That’s what allows them to become global outbreaks. Pandemics are uncommon, but influenza is one of the more frequent causes.

全球大流行病是絕大多數(shù)人類不具備免疫防護(hù)的新病原體引起的。這使得它們能席卷全球。全球大規(guī)模暴發(fā)的疫情并不常有，流感是引發(fā)流行病較常見的原因之一。

What often happens is that a novel variant of flu virus spreads around the world and then recedes, kind of like a tsunami. A few months later, it comes back and spreads around the world, or large parts of it, again.

經(jīng)常發(fā)生的情況是，流感病毒的新變異株在世界各地?cái)U(kuò)散，然后消退，有點(diǎn)像海嘯。幾個(gè)月后，它卷土重來，再次在世界各地或大部分地區(qū)擴(kuò)散。

2.What makes the first wave recede?

是什么讓第一波疫情消退？

Influenza pandemics can be temporarily beaten back by the change of seasons, moving to the southern hemisphere when the northern half of the globe heats up during its summer, and vice versa. The virus may also have infected a huge portion of people in most areas, giving them immunity from re-infection and possibly creating so-called herd immunity, which protects those who haven’t been infected by curtailing the virus’s circulation.

流感大流行可能會(huì)被季節(jié)變化暫時(shí)擊退，在北半球夏季升溫時(shí)轉(zhuǎn)移到南半球，然后再反過來。這種病毒還可能在大多數(shù)地區(qū)感染大量人口，使他們形成免疫，不會(huì)再次感染，可能會(huì)形成所謂的群體免疫，由此減少病毒傳播來保護(hù)尚未感染的人。

In the case of the coronavirus that causes Covid-19, countries around the world have adopted movement restrictions on an unprecedented scale and social-distancing measures that together keep people far enough apart so that the virus can’t easily spread.

就新冠病毒而言，世界各國都以前所未有的規(guī)模采取了行動(dòng)限制和保持社交距離的措施——這些措施使人們保持足夠遠(yuǎn)的距離，讓病毒無法輕易傳播。

3.So how does a virus come back?

病毒如何卷土重來？

There are a number of possibilities. In the case of influenza, there’s the onset of cool weather, a factor that may affect the coronavirus, too. Or the pathogen can mutate. This is another feature of flu, which mutates more or less constantly.

有幾種可能性。就流感而言，天氣會(huì)轉(zhuǎn)涼，這個(gè)因素也可能會(huì)影響新冠病毒?；蛘卟≡w可能會(huì)變異。這是流感的另一個(gè)特點(diǎn)，基本在不斷變異。

In the fall of 1918, a second wave of the historic influenza outbreak occurred and caused most of the deaths in the pandemic. Some researchers believe it was brought about by a mutation that made the virus again unrecognizable to most people’s immune systems. Another important variable is the movement of the virus to populations that haven’t been exposed before and don’t have immunity.

1918年秋天，歷史上著名的流感疫情出現(xiàn)第二波暴發(fā)，造成了那次大流行中的大多數(shù)死亡。有些研究人員認(rèn)為，那是變異造成的，變異導(dǎo)致大多數(shù)人的免疫系統(tǒng)無法識(shí)別這種病毒。另一個(gè)重要的變化因素是病毒向以前沒有接觸過它、所以不具備免疫力的人群傳播。

In addition, the World Health Organization said on April 24 that there’s no evidence yet that people who have recovered from Covid-19 and have antibodies are protected from a second infection.

另外，世界衛(wèi)生組織于4月24日表示，尚無證據(jù)表明感染新冠病毒康復(fù)且?guī)Э贵w者不會(huì)二次感染。

4.Why wasn’t there a second wave of SARS?

為什么沒有出現(xiàn)第二波非典？

The 2002-2003 outbreak of severe acute respiratory syndrome in Asia never reached the scope of a pandemic. Though caused by a coronavirus, it wasn’t as contagious as the one responsible for Covid-19. Its spread was mainly restricted to hospitals and other settings where people came in close contact with the body fluids of infected patients.

亞洲2002年至2003年暴發(fā)的非典疫情從未達(dá)到大流行的規(guī)模。盡管它是由冠狀病毒引起的，但傳染性不像新冠病毒那么強(qiáng)。其傳播主要限于人們與受感染患者的體液密切接觸的醫(yī)院和其他場(chǎng)所。

Ebola is another pathogen relatively new to humans. There have been periodic outbreaks in Africa, but while the virus is highly contagious in some settings, it hasn’t been sufficiently infectious to spread around the world like the coronavirus.

埃博拉是另一種對(duì)人類來說相對(duì)較新的病原體。非洲定期暴發(fā)埃博拉疫情，但是，盡管這種病毒在某些地方具有高度感染性，但其感染性不足以像新冠病毒那樣在全世界擴(kuò)散。

5.What are the prospects for second waves of coronavirus?

發(fā)生第二波新冠疫情的可能性有多大？

There have been hints that a second wave is a risk. Some areas that were shut down by the virus and then reopened had restrictions reimposed because of new cases. Much of the rest of the world is still struggling to get the current wave under control. Most areas that have contained the virus have done so using movement restrictions, which slow the virus’s spread but leave many people vulnerable to infection once they begin to venture out again, raising the prospect of second waves.

有跡象表明，可能會(huì)出現(xiàn)第二波疫情。由于出現(xiàn)新發(fā)病例，此前因新冠病毒而封鎖、隨后重新開放的一些地區(qū)再次實(shí)施了限制措施。其他許多國家仍在努力控制當(dāng)前這波疫情。大多數(shù)已經(jīng)控制住該病毒的地區(qū)采取了行動(dòng)限制措施，它減緩了病毒傳播，但使得許多人在恢復(fù)外出時(shí)容易受到感染，從而增大了暴發(fā)第二波疫情的可能性。

6.What could prevent them?

如何能阻止第二波疫情？

The WHO has recommended lifting movement restrictions in stages to test the effect of each before moving to greater openness. In any case, experts say, the key to keeping infections low without locking down everyone is to scale up testing and contact tracing. Health authorities need to find infected people, isolate them, and identify their recent contacts, so they can be tested as well and isolated if necessary. Eventually, it’s possible that enough people will become exposed to the coronavirus that herd immunity will develop and it will stop spreading, or that a vaccine against it will be licensed.

世界衛(wèi)生組織建議分階段取消行動(dòng)限制，以檢驗(yàn)每個(gè)階段的效果，然后再進(jìn)一步放開。專家說，無論哪種情況，在不對(duì)所有人實(shí)施封鎖的情況下保持低感染率的關(guān)鍵是加大檢測(cè)和追蹤接觸者的力度。衛(wèi)生當(dāng)局需要找出受感染者，將他們隔離，確認(rèn)他們最近的接觸者，以便對(duì)這些人進(jìn)行檢測(cè)并在必要時(shí)加以隔離。最終，有可能有足夠多的人接觸到病毒，從而形成群體免疫，病毒會(huì)停止傳播，或者等到針對(duì)這種病毒的疫苗獲得批準(zhǔn)。

來源：彭博社、參考消息網(wǎng)

編輯：yaning