An influenza pandemic, by definition, occurs only when the influenza virus mutates into something dangerously unfamiliar to our immune systems and yet is able to jump from person to person through a sneeze, cough or touch.
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- 根據定義，全球流感的致病感冒病毒株，是人類(lèi)免疫系統完全不曾接觸過(guò)的危險突變種，能經(jīng)由噴嚏、咳嗽或接觸而在人與人之間傳播。
