新冠肺炎疫情是否會在晚些時候迎來第二波？人類又該如何阻止其暴發？美國媒體最近針對這些人們關心的問題進行了解讀。
Kilian, 6, wears a protective face mask as he jumps from a bench in Igualada, Spain on Sunday, after restrictions on children going outside during the novel coronavirus outbreak were partially lifted. [NACHO DOCE/REUTERS]
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經濟造成了損害。當世界各地政府考慮何時取消這些限制措施時，每個人心中的恐懼可以用三個字表達：第二波。大家擔心的是，暫時平息之後，疫情將以新的強度捲土重來，再次導致感染病例增加、衛生系統癱瘓以及必須實施封鎖。
What’s a second wave?
什麼是第二波？
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人類不具備免疫防護的新病原體引起的。這使得它們能席捲全球。全球大規模暴發的疫情並不常有，流感是引發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.
經常發生的情況是，流感病毒的新變異株在世界各地擴散，然後消退，有點像海嘯。幾個月後，它捲土重來，再次在世界各地或大部分地區擴散。
What makes the first wave recede?
是什麼讓第一波疫情消退？
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.
流感大流行可能會被季節變化暫時擊退，在北半球夏季升溫時轉移到南半球，然後再反過來。這種病毒還可能在大多數地區感染大量人口，使他們形成免疫，不會再次感染，可能會形成所謂的群體免疫，由此減少病毒傳播來保護尚未感染的人。
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模採取了行動限制和保持社交距離的措施——這些措施使人們保持足夠遠的距離，讓病毒無法輕易傳播。
So how does a virus come back?
病毒如何捲土重來？
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，天氣會轉涼，這個因素也可能會影響新冠病毒。或者病原體可能會變異。這是流感的另一個特點，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第二波暴發，造成了那次大流行中的大多數死亡。有些研究人員認為，那是變異造成的，變異導致大多數人的免疫系統無法識別這種病毒。另一個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，世界衛生組織於4月24日表示，尚無證據表明感染新冠病毒康復且帶抗體者不會二次感染。
People walk by a billboard at Harlem's Apollo theater stating "Be Well" on April 24, 2020, in New York City. [Photo/Agencies]
Why wasn’t there a second wave of SARS?
為什麼沒有出現第二波非典？
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年暴發的非典疫情從未達到大流行的規模。儘管它是由冠狀病毒引起的，但傳染性不像新冠病毒那麼強。其傳播主要限於人們與受感染患者的體液密切接觸的醫院和其他場所。
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.
埃博拉是另一種對人類來說相對較新的病原體。非洲定期暴發埃博拉疫情，但是，儘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散。
What are the prospects for second waves of coronavirus?
發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，可能會出現第二波疫情。由於出現新發病例，此前因新冠病毒而封鎖、隨後重新開放的一些地區再次實施了限制措施。其他許多國家仍在努力控制當前這波疫情。大多數已經控制住該病毒的地區採取了行動限制措施，它減緩了病毒傳播，但使得許多人在恢復外出時容易受到感染，從而增大了暴發第二波疫情的可能性。
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.
世界衛生組織建議分階段取消行動限制，以檢驗每個階段的效果，然後再進一步放開。專家說，無論哪種情況，在不對所有人實施封鎖的情況下保持低感染率的關鍵是加大檢測和追蹤接觸者的力度。衛生當局需要找出受感染者，將他們隔離，確認他們最近的接觸者，以便對這些人進行檢測並在必要時加以隔離。最終，有可能有足夠多的人接觸到病毒，從而形成群體免疫，病毒會停止傳播，或者等到針對這種病毒的疫苗獲得批准。
本文摘自：中國日報網
立足亞洲 面向世界
傳遞論壇最新動態 促進亞洲深度合作
全球重要對話的傳達者 亞洲共同發展的瞭望者
關鍵字: second world coronavirus
