對新冠疫情的監(jiān)測發(fā)現(xiàn)，兒童的發(fā)病率較低，癥狀也較輕。這是為什么呢？科學(xué)家認為，這可能是因為兒童經(jīng)常得感冒，免疫系統(tǒng)已經(jīng)做好了充分準(zhǔn)備。

Children may be protected from coronavirus because they catch so many colds, scientists have suggested.

科學(xué)家指出，兒童經(jīng)常感冒可能會保護他們免受新冠病毒的傷害。

Figures from the Office for National Statistics (ONS) suggest children are just as likely to pick up the virus, but few ever develop serious disease, or even show symptoms.

英國國家統(tǒng)計局的數(shù)據(jù)顯示，兒童和大人一樣容易感染新冠病毒，但是發(fā)展成重癥的兒童沒有多少，有些甚至沒有表現(xiàn)出癥狀。

Now scientists have suggested that children may be resistant because their immune systems are already well primed by the common cold.

現(xiàn)在科學(xué)家指出，兒童對新冠病毒可能有抵抗力，因為普通感冒已經(jīng)讓他們的免疫系統(tǒng)做好了充分準(zhǔn)備。

The common cold is caused by four different types of coronavirus which circulate in the community and are largely harmless. But while adults pick up a cold around two to four times a year, school age children catch an average of 12 colds annually, studies have shown.

普通感冒是由社區(qū)中流行的四種不同的冠狀病毒引起的，大部分都是無害的。但是研究顯示，成年人每年大約感冒兩到四次，學(xué)齡兒童每年平均感冒12次。

Professor Sir John Bell, Regius Professor of Medicine, University of Oxford told the House of Lords Science and Technology Select Committee, that it may allow youngsters to build up some ongoing resistance that adults do not have.

牛津大學(xué)醫(yī)藥學(xué)欽定講座教授約翰·貝爾爵士告訴上議院科學(xué)技術(shù)特別委員會說，這可能會讓兒童建立起成年人沒有的抵抗力。

“How you respond may be due to the state of your existing immunity to coronaviruses generally,” he told peers.

他告訴同行說：“你對病毒的反應(yīng)可能要歸因于你對冠狀病毒群體的現(xiàn)有免疫力狀況。”

“There is an interesting speculation at the moment, that suggests that many people in young or middle aged groups may have T-cells that can already see coronavirus. It may well be able to provide some protection against this pathogen when it arrives.

“現(xiàn)在有一種有趣的猜測，就是許多年輕人或中年人可能擁有接觸過冠狀病毒的T淋巴細胞。當(dāng)人體感染冠狀病毒后，這種細胞很可能會保護人體不受病原體侵害?！?/p>

“A lot of kids get seasonal coronaviruses and it’s pretty common in our population and many will have quite a strong immunity to coronaviruses generally.

“很多孩子都會感染季節(jié)性冠狀病毒，這種病毒在我們的人口中相當(dāng)普遍，許多人對冠狀病毒群體都已擁有相當(dāng)強的免疫力?！?/p>

“That is unproven, but there is evidence now for cross-reactivity at T-cell level at least, and that well might help dampen the effects of the virus when we get it.”

“這還沒有經(jīng)過證實，但是現(xiàn)在有證據(jù)表明病毒至少在T淋巴細胞層面會發(fā)生交叉反應(yīng)，這會在感染時降低病毒的危害性?！?/p>

Studies have shown that by the age of four, some 70 percent of children already have antibodies against seasonal coronavirus, which could offer important protection.

過去的研究顯示，大約70%的兒童在四歲前已經(jīng)對季節(jié)性冠狀病毒擁有抗體，該抗體能提供重要的保護作用。

Professor Adrian Hayday, Chair, Department of Immunobiology, King's College London said the immune systems of young people may simply be better at reacting to new viruses.

倫敦國王學(xué)院免疫生物學(xué)部主任阿德里安·黑戴教授表示， 年輕人的免疫系統(tǒng)可能就是更善于應(yīng)對新病毒。

“All adults past a certain age - 30 to 35 - eventually have no thymus so their T-cells work by looking at whether they have seen something before, whereas children are very good at seeing things that are completely unknown.

“所有超過一定年齡——30到35歲——的成年人最后胸腺組織都會消失，所以他們的T淋巴細胞是否發(fā)揮作用取決于他們是否感染過這種病毒，而孩子們的T淋巴細胞則非常善于應(yīng)對完全陌生的病毒?！?/p>

The scientists also said that older people may suffer from immune cell ‘senescence’ where their immune cells start to shut down but are not cleared away and replaced with a working version.

科學(xué)家還表示，老年人可能遭受了免疫細胞的“老化”，他們的免疫細胞開始停工，但卻沒有被清除，也沒有能工作的免疫細胞來替代。

senescence[s??nesns]: n. 衰老

But Prof Bell said for most people coronavirus was not a serious illness.

但是貝爾教授說，對于大多數(shù)人而言新冠病毒不會發(fā)展成重病。

“The people who get severe disease and die, the vast majority are elderly people and when young people get this disease they tend not to suffer very much.

“發(fā)展成重癥而死亡的絕大多數(shù)人都是老年人，如果年輕人感染了病毒，他們一般都不會太嚴重?！?/p>

“That might be the state of people’s immune system at different ages. 70 percent of the people who get this are completely asymptomatic, so at one end of the spectrum this is not a bad viral disease, at the other end it’s terrible.

“這可能是因為人的免疫系統(tǒng)在不同年齡的狀態(tài)不一樣。感染新冠病毒的人有70%完全沒有癥狀，因此從一邊來看這不是一種很糟糕的病毒性疾病，但從另一邊來看這個病非常危險?！?/p>

“The vast majority of people who get this disease don’t even know they’ve had it.”

“絕大多數(shù)感染病毒的人甚至都不知道自己已經(jīng)感染上了?！?/p>

英文來源：每日電訊報

翻譯&編輯：丹妮