Placeholder Image

字幕列表 影片播放

  • - [Narrator] A COVID-19 variant first detected

  • in India in October of 2020

  • has quickly spread around the world

  • and been detected in nearly 100 countries

  • within 10 months.

  • As of July, more than 80% of known COVID cases

  • in the US are caused by the Delta variant.

  • - The Delta variant is currently the greatest threat

  • in the US to our attempt to eliminate COVID-19.

  • - The Delta variant is both more transmissible

  • and possibly more severe.

  • - [Narrator] Studies have shown that some COVID vaccines

  • are effective at preventing symptomatic illnesses

  • caused by the strain.

  • Nevertheless, as of July,

  • cases are on the rise in countries

  • where a large part of the population is vaccinated.

  • Even countries that have been previously spared

  • from the pandemic are now battling

  • a ferocious wave of infections.

  • We look at some moment in key countries

  • to understand why the deadly outbreak of Delta

  • is not just threatening the economic recovery

  • but also the return to normal around the world.

  • First, we go back to October of 2020.

  • Health authorities say the Delta variant

  • was first detected here in the state

  • of Maharashtra in India.

  • By the spring, the number of cases in India

  • began ticking up.

  • Then from March to May,

  • infections jumped 20-fold,

  • plunging the country in disarray.

  • - [Betsy] It ripped through the country.

  • Thousands and thousands of new infections every day.

  • Hospitals were completely overwhelmed

  • and they were running out of oxygen

  • for patients who needed help breathing.

  • (speaking in foreign language)

  • - [Narrator] Public health experts blamed

  • India's deadly wave on several factors.

  • There were political rallies for state elections

  • that drew large crowds.

  • There was also a religious festival in April

  • when millions of Hindus gathered to bathe

  • in the Ganges River.

  • And then a few days later,

  • the government relaxed safety measures

  • like mask wearing and social distancing.

  • But scientists say

  • what really helped accelerate the case load

  • was Delta variant's molecular composition

  • and its nine key mutations in the protein spikes

  • that surround the virus.

  • Mutations on these spikes allow the varies

  • to invade human cells more easily,

  • making the Delta variant about 50%

  • more transmissible than others.

  • By June 1st, the variant wasn't only in India

  • but detected in more than 60 countries.

  • And the United Kingdom

  • was one of the first Western countries

  • to see an alarming increase in cases

  • as Delta became the dominant strain.

  • - We're seeing cases growing by about 64% per week

  • and in the worst affected areas,

  • it's doubling every week.

  • - [Narrator] What surprised health officials

  • was that around 75% of the adult British population

  • had already received at least one dose of a vaccine

  • and about 50% was fully vaccinated.

  • - The UK's a really unfortunate situation.

  • There are good levels of vaccination there

  • but the variant took off anyway.

  • - [Narrator] And that was partly because vaccines

  • were reacting differently to Delta

  • than they had to earlier strains.

  • By mid-June, studies showed

  • that one dose of some vaccines

  • was 17% less effective

  • at preventing symptomatic illnesses caused by Delta.

  • But two doses provided good protection.

  • - The more the Delta variant is allowed to spread,

  • the greater the risk of mutations,

  • which would evade the vaccines or evade treatments.

  • And we'd kind of almost be back to the beginning.

  • - [Narrator] By late June,

  • Delta was detected in countries

  • that had been slower to vaccinate,

  • in part because they had been spared the brunt

  • of the pandemic

  • and cases began rising in these places.

  • Australia and Thailand imposed lockdowns.

  • Even Japan decided to ban spectators at the Olympics

  • because of a new wave of infections.

  • - There are many, many, many countries

  • that don't have access to vaccine yet.

  • Not many people in the population are vaccinated.

  • And this is the huge concern about this variant.

  • That it's just going to rip through these countries.

  • - [Narrator] Meanwhile, in the US,

  • as people headed into their 4th of July weekend,

  • the Delta variant had become the dominant strain.

  • People were traveling again

  • and many stopped wearing masks

  • after the CDC said it wasn't necessary

  • for those who were fully vaccinated.

  • The variant has mostly spread to areas

  • where vaccination rates have been slow.

  • In some parts of the country,

  • like in Los Angeles, authorities have asked people

  • to wear masks in indoor public places,

  • regardless of vaccination status.

  • But some public health experts say the appetite

  • for another lockdown is low.

  • - It's difficult to ask people

  • to once again adopt these measures.

  • The message is everybody needs to get vaccinated.

  • - [Narrator] So on July 4th, Biden urged people

  • to do just that

  • as the administration planned

  • to make it easier for people to get their shots,

  • like sending more mobile clinics to festivals

  • and sporting events.

  • - While the virus hasn't been vanquished,

  • we know this,

  • it no longer controls our lives.

  • It no longer paralyzes our nation

  • and it's within our power to make sure it never does again.

  • - [Narrator] And that means it's a race against time

  • to vaccinate more people around the world

  • before the coronavirus mutates against.

  • (lively music)

- [Narrator] A COVID-19 variant first detected

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

B1 中級 美國腔

Covid 的 Delta 变体如何在全球范围内快速传播(How Covid’s Delta Variant Quickly Spread Globally | WSJ)

  • 29 3
    joey joey 發佈於 2021 年 07 月 24 日
影片單字