And due to the differences in the flow of people, population density and immunity levels, the peak time of the epidemic will vary from place to place.

由于各地人口流动、人口密度和免疫水平的差异，疫情高峰时间也会有所不同。

Even if you look at this issue solely from a U.S. perspective, she says, it's in the best interest of the U.S. to boost immunity levels globally as much as possible.

她表示，即使仅从美国的角度来看这个问题，尽可能提高全球的免疫力水平也符合美国的最佳利益。