We're starting with a look at some new guidance and some questions about it when it comes to wearing masks in the United States.
Late last week, the Centers for Disease Control and Prevention said most Americans who are fully vaccinated against COVID-19 can now stop wearing masks whether they're indoors or outdoors. And that they no longer need to keep their distance from each other.
One thing to point out here is that this is guidance from the CDC, it's not national law. Many U.S. states did not require wearing masks whether people were vaccinated or not but several states that did have mask mandates removed them after the new CDC guidance came out.
Until last week, the CDC had advised that even Americans who'd been vaccinated needed to keep masks on when they were indoors or in crowds. The health agency said they still might be carrying the virus.
Now, it says the latest evidence indicates its unlikely the vaccinated people are carrying the virus so they can be mask free. Publix, Starbucks, Walmart and Walt Disney World were among the companies that changed their mask policies following the new guidance.
They created some confusion in some other businesses which are trying to decide what their policies are for customers and employees returning to work. And in schools where many students are too young to eligible for an authorized emergency use vaccine. The CDC says schools should keep mask mandates in place.
None of the vaccines has been shown to be 100 percent effective against coronavirus. There've been a number of breakthrough cases recorded when people who were fully vaccinated still tested positive for the disease. And America's union of registered nurses has spoken out against the CDC's decision, saying it's not based on science, doesn't protect public health and threatens medical patients and workers across America.
The union says it's too soon to relax mask mandates. CDC data shows that new coronavirus cases in the U.S. have dropped dramatically since their peak in January. Experts say that this is because of vaccinations and natural immunities in people who've already had the disease.
上周晚些时候，美国疾病控制和预防中心（简称CDC）表示，完全接种新冠肺炎疫苗的美国人在室内和室外均可以不再佩戴口罩 。而且也无需保持社交距离 。
这里需要指出的是，这是美国疾控中心的指导意见，并非国家法律 。无论人们是否接种了疫苗，美国许多州并未规定人们必须佩戴口罩，而在疾控中心的最新指南发布后，多个州解除了强制口罩令 。
直到上周，美国疾控中心还建议，即使是接种过疫苗的美国人，在室内或人群中也要佩戴口罩 。这个卫生机构当时表示，因为已接种疫苗人群仍可能携带病毒 。
现在，该机构表示，最新证据表明已接种疫苗人群不太可能携带病毒，因此他们可以不再佩戴口罩 。新指南公布后，美国大众超级市场、星巴克、沃尔玛和迪斯尼世界等公司修改了各自的口罩佩戴规定 。
但新指南也给某些企业带来了问题，这些企业正在设法决定适用于顾客和返岗员工的政策 。而在学校，许多学生因未到接种年龄而尚未接种获得紧急使用授权的新冠肺炎疫苗 。美国疾控中心表示，学校应该继续实施口罩强制令 。
目前，没有一种疫苗被证明对冠状病毒100%有效 。多例“突破性”病例记录表明，完全接种疫苗者仍可能感染病毒 。美国注册护士工会公开反对美国疾防中心的决定，称该决定不具备科学依据，不能保护公众健康，而且会威胁到患者和美国其他工作人员 。
美国注册护士工会表示，现在放宽口罩强制令为时过早 。美国疾控中心的数据显示，自一月份达到峰值以来，美国新增冠状病毒病例已出现大幅下降 。专家表示，这得益于疫苗接种以及人们感染病毒后产生的自然免疫力 。
1. when it comes to 谈到；涉及；
When it comes to pollution, the chemical industry is a major offender.
2. no longer 不再；已不；
This information is no longer retained within the computer's main memory.
3. come out 出版，公布；
The German Chancellor and the French President have come out in favour of direct financial aid.
4. speak out against 公开表白；大胆说出；
As tempers rose, he spoke out strongly against some of the radical ideas for selling off state-owned property.