ID 原文 译文
53984 As authorities the world over consider when to lift economy-crippling movement restrictions aimed at curbing coronavirus infections, the fear on everyone’s minds can be expressed in two words: second wave. 当世界各地政府考虑何时取消这些限制措施时，每个人心中的恐惧可以用三个字表达：第二波。
53985 The concern is that, once quelled, the pandemic will resurface with renewed strength, causing a repeat of rising infections, swamped health systems and the necessity of lockdowns. 大家担心的是，暂时平息之后，疫情将以新的强度卷土重来，再次导致感染病例增加、卫生系统瘫痪以及必须实施封锁。
53986 What’s a second wave? 什么是第二波？
53987 Pandemics are caused by new pathogens that the vast majority of humans have no immune protection against. 全球大流行病是绝大多数人类不具备免疫防护的新病原体引起的。
53988 That’s what allows them to become global outbreaks. 这使得它们能席卷全球。
53989 Pandemics are uncommon, but influenza is one of the more frequent causes. 全球大规模暴发的疫情并不常有，流感是引发流行病较常见的原因之一。
53990 What often happens is that a novel variant of flu virus spreads around the world and then recedes, kind of like a tsunami. 经常发生的情况是，流感病毒的新变异株在世界各地扩散，然后消退，有点像海啸。
53991 A few months later, it comes back and spreads around the world, or large parts of it, again. 几个月后，它卷土重来，再次在世界各地或大部分地区扩散。
53992 What makes the first wave recede? 是什么让第一波疫情消退？
53993 Influenza pandemics can be temporarily beaten back by the change of seasons, moving to the southern hemisphere when the northern half of the globe heats up during its summer, and vice versa. 流感大流行可能会被季节变化暂时击退，在北半球夏季升温时转移到南半球，然后再反过来。