“最壞的變種”在這裡

Recently CNN on-line reported the following

The 'worst variant' is here

By Eliza Mackintosh, CNN

Updated 1:24 AM ET, Thu July 14, 2022

(CNN)Nearly two-and-a-half years since the coronavirus pandemic began, the most infectious and transmissible variant yet has arrived.

Repeated Covid-19 waves have left millions of people dead, with only vaccines helping to blunt the toll. Now the virus is spreading again — evolving, escaping immunity and driving an uptick in cases and hospitalizations. The latest version of its shape-shifting, BA.5, is a clear sign that the pandemic is far from over.

The newest offshoot of Omicron, along with a closely related variant, BA.4, are fueling a global surge in cases — 30% over the past fortnight, according to the World Health Organization (WHO).

In Europe, the Omicron subvariants are powering a spike in cases of about 25%, though Dr. Michael Ryan, the executive director of WHO's Health Emergencies Program, has said that number may actually be higher, given the "almost collapse in testing." BA.5 is on the march in China, ratcheting anxieties that major cities there may soon re-enforce strict lockdown measures that were only recently lifted. And the same variant has become the dominant strain in the United States, where it accounted for 65% of new infections last week, according to the Centers for Disease Control and Prevention (CDC).

"We have been watching this virus evolve rapidly. We've been planning and preparing for this moment. And the message that I want to get across to the American people is this: BA.5 is something we're closely monitoring, and most importantly, we know how to manage it," said Dr. Ashish Jha, the White House's Covid-19 response coordinator, in a news briefing on Tuesday.

On the same day, WHO's Emergency Committee said Covid-19 remained a Public Health Emergency of International Concern — its highest level of alert, first declared on January 20, 2020 — amid rising cases, ongoing viral mutation and increasing pressure on already overstretched health systems. In a statement, the committee, which is made up of independent experts, highlighted challenges to the ongoing global Covid-19 response, including a drop-off in testing and spotty genome sequencing, raising the question of just how accurately any nation might reasonably be able to monitor BA.5.

Official data dramatically undercount the true number of infections in the US, epidemiologists say, leaving the nation with a critical blind spot as the most transmissible coronavirus variant yet takes hold. Some experts think there could be as many as 1 million new infections every day in the broader US population — 10 times higher than the official count.

As for how to manage the new wave, Jha urged Americans aged 50 and older to get second booster shots. Adults who are up to date with vaccinations are less likely to be hospitalized than those who are unvaccinated. But only about one in four adults in the US over 50 have gotten their recommended second boosters, data collected by the CDC show.

US health officials are urgently working on a plan to allow second Covid-19 boosters for all adults, a senior White House official confirmed to CNN on Monday, amid fears that younger adults' immunity may be waning as Covid-19 cases rise with the dominance of BA.5.

What makes BA.5 different? Eric Topol, a cardiologist and professor of molecular medicine at Scripps Research, has called BA.5 "the worst version of the virus we've seen." He explained in a recent newsletter: "It takes immune escape, already extensive, to the next level, and, as a function of that, enhanced transmissibility," well beyond earlier versions of Omicron.

In other words, BA.5 can easily evade immunity from previous infections and vaccines, increasing the risk of reinfection. Though the variant does not appear to lead to more severe illness, in an interview with CNN on Monday, Topol said that given the extent of BA.5's immune evasion, he expects to see an escalation in hospitalizations, as we've seen in Europe and elsewhere that the variant has taken root. "One good thing is it doesn't appear to be accompanied by the ICU admissions and the deaths as previous variants, but this is definitely concerning," he added.

Public health experts in the US may take some solace from the trajectory of the variant in Europe. WHO's Ryan said last week that while many European countries are experiencing a jump in hospitalizations, "what we're not seeing is an increase in intensive care unit admissions, so the vaccines are very much still working and it is those gaps in immunity that are causing the problem."

But still, steep reductions in Covid-19 surveillance worldwide are hindering epidemiologists' efforts as they race to trace the virus' evolution.

"Sub-variants of Omicron, like BA.4 and BA.5, continue to drive waves of cases, hospitalization and death around the world," WHO Director-General Tedros Adhanom Ghebreyesus said in a media briefing on Tuesday. "Surveillance has reduced significantly -- including testing and sequencing -- making it increasingly difficult to assess the impact of variants on transmission, disease characteristics, and the effectiveness of counter-measures."

"New waves of the virus demonstrate again that the Covid-19 [pandemic] is nowhere near over," he added.

Translation

（美國有線電視新聞網）自冠狀病毒大流行開始近兩年半以來，迄今為止最具傳染性和傳播性的變種已經到來。

反複的 Covid-19 浪潮已導致數百萬人死亡，只有疫苗有助於減少死亡人數。現在，病毒再次傳播 - 進化、逃避免疫力並推動病例和住院人數增加。其變形的最新版本 BA.5 清楚地表明病毒大流行還遠未結束。

根據世界衛生組織 (WHO) 的數據，Omicron 的最新分支及密切相關的變體 BA.4 正在推動全球病例激增 - 在過去兩週內增加了 30%。

在歐洲，Omicron 分支變體導致病例激增約 25%，儘管世衛組織突發衛生事件規劃執行主任 Dr. Michael Ryan 表示，由於“檢測幾乎崩潰”，這個數字實際上可能更高。 BA.5 正在中國傳播，這加劇了人們對中國主要城市可能很快會重新實施最近才解除的嚴格封鎖措施的擔憂。根據美國疾病控制與預防中心 (CDC) 的數據，同樣的變種已成為美國的主要毒株，上週它佔新感染病例的 65%。

白宮 Covid-19 應對協調員Dr. Ashish Jha 在周二的新聞發布會上說: “我們一直在觀察這種病毒的迅速發展。我們一直在為這一刻做計劃和準備。我想向美國人民傳達的信息是：BA.5 是我們正在密切監測的東西，而且最重要的是，我們知道如何對應它” 。

同一天，世衛組織突發事件委員會表示，在Covid-19病例不斷增加中的的情況下, 它仍然是國際關注的突發公共衛生事件 - 這是世衛的最高警戒級別並是於 2020 年 1 月 20 日首次宣布 、病毒不斷變異以及對已經不堪重負的衛生系統的壓力越來越大。 由獨立專家組成的委員會在一份聲明中強調了當前全球 Covid-19 應對措施面臨的挑戰，包括檢測下降和基因組測序參差，這引發了一個問題，即各國能夠監控BA.5的準確度有多大。

流行病學家說，美國官方數據大大低估了它的真實感染人數，使該國成為迄今為止傳播性最強的冠狀病毒變種的關鍵盲點。一些專家認為，在更廣泛的美國人口中，每天可能有多達 100 萬新感染病例 - 比官方統計數字高出 10 倍。

至於如何管理新的浪潮，Jha 敦促 50 歲及以上的美國人進行第二次加強注射。與未接種疫苗的人相比，接種了最新疫苗的成年人住院的可能性更小。但 CDC 收集的數據顯示，在美國 50 歲以上的成年人中，只有大約四分之一的人獲得了被他們推薦的第二次加強注射。

一位白宮高級官員周一向 CNN 證實，美國衛生官員正在緊急制定一項計劃，為所有成年人提供第二次 Covid-19 加強注射，因為擔心隨年輕人的免疫力可能會減弱中, Covid-19 病例以BA.5顯著增加。

是什麼令 BA.5 與眾不同？ Scripps Research 的心臟病學家和分子醫學教授 Eric Topol 稱 BA.5 是 “我們見過的最糟糕的病毒樣版”。他在最近的通訊中解釋說：“它將已經廣泛的免疫逃逸提升到一個新的水平，因此作為一個功能，增強了傳播性”, 遠遠超出了早期版本的 Omicron。

也就是說，BA.5很容易逃避以前感染和疫苗產生的免疫力，增加再感染的風險。儘管該變體似乎不會導致更嚴重的疾病，但 Topol 在周一接受 CNN 採訪時表示，鑑於 BA.5 免疫逃避的程度，他預計住院人數會增加，正如我們在歐洲及其他地方看到那樣, 在那裡該變體已經紮根。他補充說: “一件好事是它似乎沒有像以前的變種那樣相連到進入ICU和死亡，但這絕對是令人擔憂的”。

美國的公共衛生專家可能會從歐洲變種的軌跡中得到一些安慰。世衛組織的 Ryan上週表示，雖然許多歐洲國家的住院人數激增，但“我們沒有看到重症監護病房入院人數的增加，因此疫苗仍在發揮作用，正在造成問題的是免疫方面的漏洞。”

但是，全球範圍內監測 Covid-19的急劇減少,阻礙了流行病學家在急切追踪病毒演變過程中的努力。

世衛組織總幹事 Tedros Adhanom Ghebreyesus 在周二的媒體簡報中說: “Omicron 的分支變體，如 BA.4 和 BA.5，繼續在世界範圍內推動病例、住院和死亡的浪潮” 。 “監測已經大大減少 - 包括檢測和序測 - 使得對評估傳播變異、疾病特徵,和對策有效性的影響變得越來越困難。”

他補充說： “新一波病毒再次表明，Covid-19 [大流行] 還遠未結束。”

So, nearly two-and-a-half years since the coronavirus pandemic begins, the most infectious and transmissible variant so far has arrived. It is the newest offshoot of Omicron, BA.5 that are fueling a global surge in cases, according to the World Health Organization (WHO). New waves of the virus demonstrate that the Covid-19 is not yet over.