VOA慢速英语--辉瑞称第三针新冠疫苗可预防奥密克戎

Pfizer Says Third COVID Shot Protects against Omicron

American drugmaker Pfizer said on Wednesday that the third shot, or booster, of its COVID-19 vaccine¹ will protect people against the Omicron variant² of the virus.

Pfizer and its German partner BioNTech said early lab tests show the booster increased levels of virus-fighting antibodies by "25-fold."

The Pfizer research is early and has not been independently examined.

A statement from Pfizer's top officer, Albert Bourla, said the two-shot vaccine still offers protection against severe disease caused by Omicron. But, Bourla said, "it's clear from these preliminary data that protection is improved with a third dose of our vaccine."

The company also said it has started to develop a COVID-19 vaccine against Omicron. If needed, the new vaccine will be ready by March 2022.

The findings are similar to a small study published by researchers at the Africa Health Research Institute in South Africa on Tuesday. The South African study also suggested that a third shot might help against Omicron infection.

However, Reuters reported that a study at the University Hospital of Frankfurt, Germany, found reduced antibody levels against Omicron even after three shots.

Independent experts have not reviewed the studies.

Health officials still do not know how big of a threat Omicron really is. The Delta³ variant is still responsible for most of the cases, especially in the United States.

Omicron was first identified in Africa on November 9 and reported to the World Health Organization (WHO) on November 24. Two days later, the WHO designated it a variant of concern, or VOC.

The agency said Omicron "has a large number of mutations, some of which are concerning." A mutation⁴ is a change in the genetic⁵ material of a virus. The WHO added that early evidence suggests "an increased risk of reinfection with this variant, as compared to other VOCs."

Several countries, including the United States, Brazil, Japan, and Israel, restricted travelers from some African countries. But the variants⁶ have since been identified throughout Europe, North America and Australia.

Words in This Story

fold - n. a word to describe a quantity changes between an original and a subsequent measurement

preliminary - adj. coming before something

dose - n. the amount of medicine that is taken at one time

1 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。

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 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 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。

5 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

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