Pfizer and its German partner BioNTech said early lab tests show the booster increased levels of virus-fighting antibodies by "25-fold."
辉瑞及其德国合作伙伴生物新科技公司表示，早期实验室测试表示，加强针将抵抗病毒的抗体水平提高了25倍。

The Pfizer research is early and has not been independently examined.
辉瑞的研究尚处于早期阶段，尚未经过独立审查。

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."
辉瑞高层阿尔伯特·博拉发表声明称，两针疫苗仍然能够防止奥密克戎导致的重症。但是博拉表示：“从这些初步数据中可以清楚看到，我们的第三针疫苗可以提高保护作用。”

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.
该公司还称其已经开始开发针对奥密克戎的新冠肺炎疫苗。如果有需要，这种新疫苗将于2022年3月准备就绪。

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.
该研究结果与南非非洲健康研究所研究人员周二发表的一项小型研究类似。南非的研究也表明，第三针可能有助于防止奥密克戎感染。

However, Reuters reported that a study at the University Hospital of Frankfurt, Germany, found reduced antibody levels against Omicron even after three shots.
然而，路透社报道称，德国法兰克福大学医院的一项研究发现，即使在注射第三针之后，针对奥密克戎的抗体水平也会降低。

Independent experts have not reviewed the studies.
独立专家尚未对这些研究进行审查。

Health officials still do not know how big of a threat Omicron really is. The Delta variant is still responsible for most of the cases, especially in the United States.
卫生官员仍然不知道奥密克戎的威胁到底有多大。德尔塔变种仍然是大多数病例的罪魁祸首，尤其是在美国。

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.
奥密克戎最初于11月9日在非洲被确认，并于11月24日向世卫组织报告。世卫组织在两天之后将其定为需要关切的变种。

The agency said Omicron "has a large number of mutations, some of which are concerning." A mutation is a change in the genetic material of a virus. The WHO added that early evidence suggests "an increased risk of reinfection with this variant, as compared to other VOCs."
该机构表示，奥密克戎存在大量突变，其中一些令人担忧。突变是指遗传物质的变化。世卫组织还表示，早期证据表明，与其它令人关切的变种相比，奥密克戎再度感染的风险更大。

Several countries, including the United States, Brazil, Japan, and Israel, restricted travelers from some African countries. But the variants have since been identified throughout Europe, North America and Australia.
包括美国、巴西、日本和以色列在内的几个国家限制了来自一些非洲国家的旅客。但此后在整个非洲、北美和澳大利亚都发现了这种变种。