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每日英語跟讀 Ep.K294: Omicron rewrites COVID plan for 2022
As the Omicron variant gains momentum in Europe and the United States, scientists are rewriting their expectations for the COVID-19 pandemic next year. Just weeks ago, disease experts were predicting that countries would begin to emerge from the pandemic in 2022 after enduring a series of surges driven by the Alpha, Beta, Gamma and Delta variants. First among them would be populations with a significant amount of exposure to the coronavirus, through a combination of infections and vaccination.
In those places, COVID was expected to ease into an endemic disease, hopefully with less-severe periodic or seasonal outbreaks. Vaccines, available for much of 2021 only in wealthy nations, could reach the majority of the global population by the end of the year ahead.
But the rapid spread of the highly-mutated Omicron variant, identified in late November, and its apparent ability to reinfect people at a higher rate than its predecessors, is undermining that hope.
Already, countries are reverting to measures used earlier in the pandemic: restricting travel, reimposing mask requirements, advising against large gatherings for the winter holidays. While it is not quite back to square one, much more of the world will need to be vaccinated or exposed to COVID to get past the worst of the pandemic, disease experts said.
More than 270 million people have been infected with COVID, according to the World Health Organization, while an estimated 57 percent of the global population has received at least one vaccine dose, representing potential protection that did not exist two years ago.
“Even if that immunity is not as good against Omicron, it doesn’t mean that it’s worthless. And that immunity is more effective against serious illness than it is against getting infected at all,” said Dr. David Dowdy, an infectious disease epidemiologist at Johns Hopkins.
So far, most of the studies looking at the effectiveness of vaccines against Omicron have focused on neutralizing antibodies, which latch on to the virus and prevent it from entering and infecting cells. Blood test results from fully vaccinated people show Omicron has learned to escape neutralization; a booster dose might restore that protection.
Immune system T cells, which destroy infected cells, also appear still to be able to recognize the variant. Many experts believe this second line of defense will prevent hospitalizations and deaths.
摧毀受感染細胞的免疫系統T細胞似乎仍能識別Omicron變種。許多專家認為，這第二道防線可避免住院及死亡。Source article: https://www.taipeitimes.com/News/lang/archives/2021/12/28/2003770287