返美不用境外隔离？1月31日总统限制入境行政令sec. 2 (ix)

最近发现行政令里豁免条件有这么一条 原文如下
(ix)    any alien whose entry would not pose a significant risk of introducing, transmitting, or spreading the virus, as determined by the CDC Director, or his designee;
不知道该如何解读