1957 58:"亞洲型流感"H2N2大流行

1957-58：“亞洲型流感”H2N2大流行1957-58: "Asian flu" H2N2 Pandemic

該病毒首先在中國得到確認，粗略估算導致七萬美國人死亡。該病毒自1968年起就沒在人類中間流行了，因此，三十歲以下的人都不具備該病毒的免疫力。得益於先進的科學技術，這種病毒很快得到確認，至1957年8月，就能有限制地供應疫苗了。雖然如此，在1957年秋季及1958年1至2月還是爆發了兩次傳染高潮。老年人死亡率最高。

First identified in China, this virus caused roughly 70,000 deaths in the United States. Because this strain has not circulated in humans since 1968, no one under 30 years old has immunity to it. The virus was quickly identified, due to advances in scientific technology, and a vaccine was available in limited supply by August 1957. Still, two waves of infection struck, in the fall of '57 and then January-February of '58. The elderly had the highest death rates.