Omicron vs. Delta: Battle of the Variants

Scientists are examining available data to try to understand who might win the battle of the coronavirus variants².

Right now, the Delta³ variant¹ is the dominant⁴ variant in the world. But after looking at data from South Africa and Britain, some scientists say the Omicron variant may soon overtake it.

"It's still early days, but ... Omicron is likely to outcompete Delta in many, if not all, places," said Dr. Jacob Lemieux. He researches coronavirus variants for a group led by Harvard Medical School.

But other experts said it is too soon to know whether Omicron will spread more quickly and easily than delta.

Matthew Binnicker is a virus expert at the Mayo Clinic in Rochester, Minnesota. He said "we'll know in about two weeks" whether Omicron will overtake Delta. He noted⁵ that the U.S. is still seeing "significant surges" of the Delta variant.

Many important questions about Omicron remain unanswered. It is still unclear if the virus causes milder or more severe illness. It is also not yet known if it might escape immunity⁶ from earlier COVID-19 illnesses or vaccines⁷.

On the issue of spread, scientists point to what is happening in South Africa, where Omicron was first found. Omicron has quickly spread there and has nearly become the dominant strain. Health experts worry the country is at the start of a new wave that may overcrowd hospitals.

In the middle of November, South Africa averaged less than 200 COVID-19 cases per day. But last week, the country saw more than 10,000 cases per day. Experts say omicron makes up more than 90 percent of the new cases in Gauteng province, the center of the new wave. The new variant is quickly spreading and becoming dominant in South Africa's eight other provinces, as well.

Willem Hanekom is director of the Africa Health Research Institute in South Africa.

"The virus is spreading extraordinarily⁸ fast," Hanekom said. "If you look at the slopes of this wave that we're in at the moment, it's a much steeper slope than the first three waves that South Africa experienced."

Scientists say it is unclear whether Omicron will act the same way in other countries as it has in South Africa. But in Britain, Lemieux said, "we're seeing what appears to be a signal of exponential increase of Omicron over Delta."

In the United States, "there's still a lot of uncertainty," he said. But "based on what we've observed in South Africa, it's likely to become the dominant strain in the coming weeks and months and will likely cause a surge in case numbers."

It is not yet known what such a surge would mean for public health.

Hanekom said early data from South Africa show that reinfection rates are much higher with Omicron than earlier variants. That would suggest the virus is escaping some immunity. It also shows the virus seems to be infecting younger people, mostly those who are unvaccinated. Early information also shows most cases in hospitals have been mild.

But experts say the situation could be different in other parts of the world or in different groups of patients.

"It'll be really interesting to see what happens when more infections potentially occur in older adults or those with underlying¹⁰ health conditions," Binnicker said.

As the world waits for answers, scientists suggest people do all they can to protect themselves.

If "people are not vaccinated⁹ they should get vaccinated," Lemieux said. "If people are eligible¹¹ for boosters, they should get boosters, and then do all the other things that we know are effective for reducing transmission."

Words in This Story

variant — n. different in some way from others of the same kind

dominant — adj. more important, powerful, or successful than most or all others

significant — adj. large enough to be noticed or have an effect

strain — n. a group of closely related plants or animals

steep — adj. going up or down very quickly

exponential — adj. very fast ; increasingly rapid

eligible — n. able to be chosen for something

booster shot — n. an extra amount of a vaccine that is injected with a needle into a person or animal to help protect against a disease

1 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。

2 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

3 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。

4 dominant   

adj.支配的，统治的；占优势的；显性的；n.主因，要素，主要的人(或物)；显性基因

参考例句：

• The British were formerly dominant in India.英国人从前统治印度。
• She was a dominant figure in the French film industry.她在法国电影界是个举足轻重的人物。

5 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

6 immunity   

n.优惠；免除；豁免，豁免权

参考例句：

• The law gives public schools immunity from taxation.法律免除公立学校的纳税义务。
• He claims diplomatic immunity to avoid being arrested.他要求外交豁免以便避免被捕。

7 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。

8 extraordinarily   

adv.格外地；极端地

参考例句：

• She is an extraordinarily beautiful girl.她是个美丽非凡的姑娘。
• The sea was extraordinarily calm that morning.那天清晨，大海出奇地宁静。

9 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？

10 underlying   

adj.在下面的，含蓄的，潜在的

参考例句：

• The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
• This word has its underlying meaning.这个单词有它潜在的含义。

11 eligible   

adj.有条件被选中的；(尤指婚姻等)合适(意)的

参考例句：

• He is an eligible young man.他是一个合格的年轻人。
• Helen married an eligible bachelor.海伦嫁给了一个中意的单身汉。