VOA慢速英语2021--“德尔塔”传播更快,症状更严重

Delta¹ Variant² Spreads Quicker, Makes People Sicker

Many countries around the world are currently experiencing a new wave of COVID-19 infections caused by the Delta variant.

As a result, disease experts are working quickly to learn whether the latest version of coronavirus is making people - mainly the unvaccinated - sicker than the earlier version.

The Delta variant was first identified in India. Now, it is the main type of SARS-CoV-2 virus worldwide.

The U.S. Centers for Disease Control and Prevention warned that the Delta variant is "likely more severe" than earlier versions of the virus. This CDC report was made public on July 30.

In this report, the U.S. health agency used research in Canada, Singapore, and Scotland. This research showed that people infected with the Delta variant were more likely to be hospitalized than patients earlier in the pandemic.

In addition, it is likely that the Delta variant spreads more easily. This is also adding to a greater number of severe cases arriving at hospitals, the experts said.

In interviews with Reuters, disease experts said the research suggests a greater risk from the Delta variant. However, the study populations were limited. And the findings have yet to be reviewed by outside experts.

Doctors treating patients infected with Delta said COVID-19 symptoms appeared more quickly. And in many areas, there was an overall increase in serious cases. But experts said more work is needed to compare outcomes among larger numbers of individuals.

Shane Crotty is a virologist at the La Jolla Institute for Immunology in San Diego, California. Crotty said the clearest sign that the Delta variant may cause more severe disease comes from the Scotland study. That study found that Delta roughly doubled the risk of hospitalization compared to an earlier version of the virus.

The majority of hospitalizations and deaths from coronavirus in the United States are happening to people who have not been vaccinated³. There is also evidence, however, that the vaccines⁵ do not work as well for people with poor immune systems, including the elderly.

Healthy, vaccinated individuals who contract COVID-19 will most likely experience a weak form of the disease, said Dr. Gregory Poland. He is an infectious disease expert at the Mayo Clinic, a not-for-profit healthcare provider and research center in the U.S. Or, he added, they might be asymptomatic. "But," Poland warned, "they can pass it on to family members and others who may not be so lucky."

He said people will "have to be vaccinated and masked or we will, for the fourth time now," have to suffer through another wave of the virus.

Poland said that "out of that will come worse variants⁶." That is because the virus mutates as it spreads, producing new variants.

Other doctors said patients infected with Delta appear to become ill more quickly. They added that, in some cases, the symptoms are more severe than earlier in the pandemic.

"We are seeing more patients requiring oxygen sooner," said Dr. Benjamin Barlow. He is chief medical officer at American Family Care, a collection of urgent healthcare facilities in the U.S.

Dr. Michelle Barron is a senior medical director of infection prevention and control at Colorado's UCHealth. She compares the Delta variant to a dangerous wildfire that is spreading quickly.

Research from China suggests that the Delta variant copies itself much faster and makes 1,000 times more virus in the body compared to the original strain. This, Barron said, is the biggest danger of this new wave.

David Montefiori is director of the Laboratory for AIDS Vaccine⁴ Research and Development at Duke University Medical Center in the U.S. He said the Delta variant is more infectious and symptoms appear faster, especially for the unvaccinated.

Montefiori said on a webcast last week, "It (is) not just easier to transmit, it makes you sicker."

Words in This Story

variant – n. one that exhibits variation from a type, norm, or wild type : mutation⁷

symptom – n. a noticeable change in the body or its functions that indicates the presence of a disease or other disorder⁸ : asymptomatic – medical adj. having or showing no symptoms of disease

contagious⁹ – adj. able to be passed from one individual to another through contact

immune system – n. the system that protects your body from diseases and infections

mutate – v. to cause (a gene) to change and create an unusual characteristic in a plant or animal : to cause mutation in (a gene)

original – adj. happening or existing first or at the beginning

strain – n. a group of closely related living things that look similar but possess one or more unique characteristics

transmit – v. to give or pass (information, values, etc.) from one person to another

1 delta   

n.（流的）角洲

参考例句：

• He has been to the delta of the Nile.他曾去过尼罗河三角洲。
• The Nile divides at its mouth and forms a delta.尼罗河在河口分岔，形成了一个三角洲。

2 variant   

adj.不同的，变异的；n.变体，异体

参考例句：

• We give professional suggestions according to variant tanning stages for each customer.我们针对每位顾客不同的日晒阶段，提供强度适合的晒黑建议。
• In a variant of this approach,the tests are data- driven.这个方法的一个变种，是数据驱动的测试。

3 vaccinated   

[医]已接种的，种痘的，接种过疫菌的

参考例句：

• I was vaccinated against tetanus. 我接种了破伤风疫苗。
• Were you vaccinated against smallpox as a child? 你小时候打过天花疫苗吗？

4 vaccine   

n.牛痘苗，疫苗；adj.牛痘的，疫苗的

参考例句：

• The polio vaccine has saved millions of lives.脊髓灰质炎疫苗挽救了数以百万计的生命。
• She takes a vaccine against influenza every fall.她每年秋季接种流感疫苗。

5 vaccines   

疫苗，痘苗( vaccine的名词复数 )

参考例句：

• His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
• The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。

6 variants   

n.变体( variant的名词复数 )；变种；变型；（词等的）变体

参考例句：

• Those variants will be preserved in the'struggle for existence". 这些变异将在“生存竞争”中被保留下来。 来自辞典例句
• Like organisms, viruses have variants, generally called strains. 与其他生物一样，病毒也有变种，一般称之为株系。 来自辞典例句

7 mutation   

n.变化，变异，转变

参考例句：

• People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
• So far the discussion has centered entirely around mutation in the strict sense.到目前为止，严格来讲，讨论完全集中于围绕突变问题上。

8 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

9 contagious   

adj.传染性的，有感染力的

参考例句：

• It's a highly contagious infection.这种病极易传染。
• He's got a contagious laugh.他的笑富有感染力。