據美國疾控中心稱，今年的流感季節爆發得特別猛惡，是自號稱“近年最嚴重流感季”的2014-2015流感季以來最嚴重的一次。

美國疾控中心在最近的一篇文章中稱：“美國流感疫情高活動性的州由21個上升到了26個，另外紐約市也是今冬流感高發地區。報稱流感大面積爆發的州也由36個上升到46個。流感樣疾病的發病率由4.9%上升到了5.8%。這些指標已經接近2014-2015流感季的峰值，而那一年也是近年來流感疫情最嚴重的一年。”加利福尼亞等州的急診室里前來就診的流感患者已經人滿為患。

今冬流感的普遍癥狀

據美國疾控中心稱，今冬流感有以下常見癥狀：發燒、惡寒、咳嗽、咽痛、流涕、身體疼痛、頭痛、乏力等（流感患者可能會同時出現以上兩三種癥狀）。有些流感患者還伴有腹瀉和嘔吐。

為何今冬流感疫情特別危險

目前流感的疫情是由于很多因素共同造成的。有些衛生官員稱，今冬的流感疫情只是“中度嚴重”，而且尚未達到頂峰（2月通常是流感疫情最嚴重的月份）。首先，美國多地今年都遭遇了近年罕見的嚴寒，使得流感病毒具備了長時間傳播的條件，使得疫情更加頑固。

再來說說流感疫苗的事。去年流感疫苗的有效性為39%，今冬流感疫苗的有效性能否達到去年的水平，尚不得而知。有些人認為，今冬流感疫苗的有效性或將低于30%，不過最后的數字只有到今冬流感季結束時才能知道（通常是每年5月份左右）。流感疫苗的有效性通常在40%到60%左右，因為科學家們在量產疫苗前，是不知道這個冬天會流行哪一型流感的，所以他們在研制時免不了要靠一些猜測。每一年都有數萬人因流感住院，還有數萬人因流感而死亡。小孩、老人和免疫力低下人群尤其高危。

另外，就算你接種了某幾型流感的疫苗，你可能也無法躲過其他幾種類型的流感。今冬傳播范圍最大的H3N2流感又是公共衛生專家眼中尤為難對付的一種。這種流感病毒更易引發嚴重癥狀，并在小孩和老人中造成更高的死亡率。

現在打疫苗是不是晚了？

好消息是，打流感疫苗什么時候都不晚！雖然有人質疑今冬流感疫苗的有效性，但我們還是推薦有條件者盡量去接種流感疫苗。

在美國，流感疫苗的接種費用基本是可以在工作單位通過醫保程序報銷的，在沃爾格林和CVS等各大零售藥店均可接種。即便是不走醫保程序，打一針流感疫苗的費用也才不到20美元。雖然每年接種流感疫苗的理想時間是秋天，但是現在接種也不晚。畢竟疫苗就是為了保護那些抗病能力沒有你那么強的人而設計的。（財富中文網）

譯者：樸成奎

The 2018 flu season is shaping up to be bad—potentially the worst one since 2014-2015, which was “the most severe season in recent years,” as the Centers for Disease Control (CDC) says in its latest flu outbreak update.

“The number of jurisdictions experiencing high activity went from 21 states to 26 states and New York City and the number of states reporting widespread activity went from 36 to 46,” wrote the public health agency in a recent post. “Influenza-like illness (ILI) went from 4.9% to 5.8%. ?These indicators are similar to what was seen at the peak of the 2014-2015 season, which was the most severe season in recent years.” In some states, like California, emergency rooms have already been overwhelmed with people suffering from the flu.

Common 2018 flu symptoms

Here are the tell-tale signs of having the flu, according to the CDC: fever and/or chills, cough, sore throat, a runny and/or stuffed nose, body aches, headaches, and fatigue (flu symptoms may present in groups of two or three or all at once). Some flu patients also experience diarrhea and vomiting.

Why the 2018 flu outbreak could be especially deadly

There are a number of factors driving the current flu season, which is already being called “moderately severe” by health officials and has yet to peak (February is usually when flu season is worst). For one thing, it’s been a particularly cold winter in many parts of the U.S., which makes for a more resilient and longer-lingering influenza virus.

And then there’s the matter of the current flu vaccine. It’s unclear if the flu shot will match last year’s effectiveness of about 39%; some estimates have pegged this year’s vaccine’s effectiveness at closer to 30%, although the final numbers will remain unknown until the end of flu season, which can last through May. The flu vaccine is typically somewhere between 40% and 60% effective since scientists have to use some guesswork as to the strains that will be floating around before mass producing the vaccine. Hundreds of thousands of people are hospitalized and tens of thousands die from the flu in any given year, and the young, old, and immune-compromised are at the highest risk.

Furthermore, getting vaccinated for certain strains won’t necessarily protect you from other flu types that are going around. And the dominant strain this year, H3N2, is one that public health experts decry as a particularly nasty one. In fact, it’s a strain that’s likely to lead to more severe symptoms and more deaths among the young and the old.

Is it too late to get a flu shot?

Now for the good news: It isn’t too late to get the flu shot! And, despite concerns about this year’s flu vaccine effectiveness, everyone is still recommended to get one.

Flu shots are often available for free through employer health programs or at retail clinics such as Walgreens and CVS. Even without insurance, a shot will cost less than $20 out of pocket. And it’s still a good idea to receive your flu shot even though the ideal time is in the fall; after all, the vaccine is meant to protect others who might not be able to cope with the sickness as well as you.