疫情的陰雲還未散去，前不久又在世界各地發現了多個新冠病毒新變種，其中以在英國、南非和巴西出現的幾個變種威力最強。這些變種有多危險？最近陸續上市的新冠疫苗對這些變種是否有效？來看看專家怎麼說。
A member of medical staff takes a coronavirus test sample of a woman as people are asked to get a coronavirus test after a primary school reported an outbreak of the more transmissible British variant of the coronavirus disease (COVID-19) in Bergschenhoek, Netherlands January 13, 2021. REUTERS/Piroschka van de Wouw
New variants of coronavirus are emerging that are more infectious than the original one that started the pandemic.
現階段湧現出的新冠病毒新變種比疫情初期的毒株更具傳染性。
Scientists are urgently studying these mutated versions to understand what threat they pose.
科學家正迫切地研究這些變種毒株，以了解它們的威脅性有多大。
Experts' concerns currently focus on a small number of new variants of coronavirus:
專家們目前最關注的是以下幾種新冠病毒新變種：
A UK variant that has become dominant in much of Britain and has spread to more than 50 other countries
出現在英國的變種：在英國大部分地區蔓延，並傳播到50多個其他國家
A South Africa variant that has also been found in at least 20 other countries, including the UK
出現在南非的變種：除南非以外，在包括英國在內的至少20個國家也發現了這一變種
A new variant from Brazil
巴西新出現的變種
It's not unexpected that new variants have developed - all viruses mutate as they make new copies of themselves to spread and thrive.
出現新變種，這是意料之中的事，因為所有病毒在複製過程中都會變異，這樣才有利於傳播和繁殖。
There are many thousands of different versions, or variants, of Covid circulating.
當前在傳播過程中的新冠病毒變種版本多達數千甚至數萬個。
Most of these differences are inconsequential. A few can even be harmful to the virus's survival. But some can make it more infectious or threatening.
大部分變異都是無關緊要的。其中有少數變異甚至不利於病毒的生存。但是有些變異則會讓病毒更具傳染性或威脅力。
Firefighters from the Marins-Pompiers of Marseille (Marseille Naval Fire Battalion) take samples in Marseille sewage water to detect the concentration of coronavirus traces and the presence of the new UK variant of the virus in Marseille, France, January 13, 2021. REUTERS/Eric Gaillard
新冠病毒新變種的威脅力有多大？
It's suspected that the UK, South Africa and Brazil variants could be much more contagious or easy to catch than earlier versions.
有人懷疑，英國、南非和巴西出現的變種可能比早期毒株的傳染性要強得多。
All three have undergone changes to their spike protein - this is the part of the virus which attaches to human cells.
這三種毒株的纖突蛋白都發生了變異，纖突蛋白是病毒附著到人體細胞的部分。
As a result, these variants seem to be better at infecting cells and spreading.
因此，這些變種似乎更容易感染人體細胞和傳播。
Experts think the UK or "Kent" strain emerged in September and may be up to 70% more transmissible or infectious, although latest research by Public Health England puts it between 30% and 50%.
專家認為，9月份在英國發現的「肯特」變種傳染性可能要高出70%，不過英格蘭公共衛生署最近的研究認為該變種的傳染性比原毒株高出30%到50%。
The South Africa variant emerged in October, and it has more potentially important changes in the spike protein than the UK variant.
10月份在南非發現的變種在纖突蛋白上發生的變異可能比英國變種更厲害。
It has one of the same mutations as the UK one, plus two more that scientists think may interfere more with vaccine effectiveness. One of these may help the virus evade parts of the immune system called antibodies.
南非的變種毒株的纖突蛋白發生的其中一處變異和英國變種相同，另外還有兩處變異，科學家認為可能會干擾疫苗的有效性。其中一處幹擾疫苗的變異可能會幫助病毒躲避人體免疫系統中的部分抗體。
The Brazil variant emerged in July and was recently detected in four travellers arriving in Japan from Brazil. It has three key mutations in the spike protein that make it similar to the South Africa one.
最近在從巴西抵達日本的四名旅客身上檢測到的變種毒株是在去年7月份在巴西出現的。這一變種的纖突蛋白有三處關鍵變異和南非出現的變種相似。
A health worker prepares an injection with a dose of the Pfizer-BioNTech COVID-19 vaccine, as the coronavirus disease (COVID-19) outbreak continues, at Balafia nursing home, in Lleida, Spain, December 27, 2020. REUTERS/Albert Gea
疫苗對新變種有效嗎？
The current vaccines were designed around earlier variants, but scientists are confident that they should still work against the new ones, although perhaps not quite as well.
當前的疫苗是針對早期毒株設計的，但是科學家相信它們對新變種也有效，不過可能有效性會打折扣。
Lab studies are underway to check this.
實驗室正在開展研究以確認疫苗是否對新變種有效。
Vaccines train the body to attack several parts of the virus, however, not just these sections of the spike protein.
疫苗會訓練人體攻擊病毒的幾個部位，不只是攻擊纖突蛋白的特定部位。
Variants could emerge in the future that are more different again.
未來的變種可能還會發生更大的變異。
Even in the worst case scenario, the vaccines could be redesigned and tweaked to be a better match - in a matter of weeks or months, if necessary, say experts.
專家表示，即使最壞的情況發生了，人類也可以重新設計和調整疫苗，以更好地匹配新變種，如果有必要的話，數周或數月內就可完成。
As with flu vaccines, where a new shot is given each year to account for any changes in circulating flu viruses, something similar could happen for coronavirus.
流感疫苗每年都要注射以應對流感病毒在傳播過程中的變異，新冠疫苗可能也會如此。
新變種是否更危險？
There is currently no evidence to suggest that any of them cause more serious illness.
目前沒有證據表明任何一個變種會導致更嚴重的疾病。
Measures such as washing your hands, keeping your distance from other people and wearing a face covering will still help prevent infections, and because the new variants spread more easily it is important to be extra vigilant.
勤洗手、同他人保持距離和佩戴口罩等措施仍然有助於防止被感染，但因為新變種更容易傳播，所以我們應當格外警惕。
英文來源：BBC
翻譯&編輯：丹妮
來源：中國日報網