The omicron variant of COVID-19 is well on its way to becoming the dominant strain in New England, but it isn't yet, despite becoming far more common in just a week.
Omicron accounted for 37.7% of the total COVID cases in Massachusetts, Connecticut, New Hampshire, Rhode Island, Maine and Vermont between Dec. 12 and Dec. 18, according an update from the U.S. Centers for Disease Control and Prevention on Monday.
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That's a major jump from the week before, when omicron accounted for 1.7% of cases, and the week before that, when it represented 0.3% of cases.
The variant's spread is so fast that it was only officially confirmed in every New England state on Sunday, when Vermont announced its first case. Still, the delta variant remains, for now, dominant in New England -- it accounts for 62.1% of cases in New England in the latest CDC update.
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That's not the case for the country as a whole. Nationally, omicron accounted for 73% of new infections last week, nearly a six-fold increase in omicron's share of U.S. infections in just seven days. In the region including New York and New Jersey more than nine out of 10 COVID cases are now the omicron variant, up from one in four the week before. And in the Southeast, more than 95% of cases are omicron.
Dr. Ashish Jha, dean of the Brown School of Public Health, called omicron's rise in the U.S. "so fast," adding it "is now essentially everywhere." But he also said that common measures to combat COVID will continue to help.
Much about the omicron variant remains unknown, including whether it causes more or less severe illness. Early studies suggest the vaccinated will need a booster shot for the best chance at preventing omicron infection but even without the extra dose, vaccination still should offer strong protection against severe illness and death.
“All of us have a date with omicron,” said Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security. “If you’re going to interact with society, if you’re going to have any type of life, omicron will be something you encounter, and the best way you can encounter this is to be fully vaccinated.”
Adalja said he was not surprised by the CDC data showing omicron overtaking delta in the U.S., given what was seen in South Africa, the U.K. and Denmark. He predicted spread over the holidays, including breakthrough infections among the vaccinated and serious complications among the unvaccinated that could stress hospitals already burdened by delta.
Source: CoVariants
Amy O’Kruk/NBC
CDC’s estimates are based on thousands of coronavirus specimens collected each week through university and commercial laboratories and state and local health departments. Scientists analyze their genetic sequences to determine which versions of the COVID-19 viruses are most abundant.
Various new variants of COVID have swept across the globe since the start of the pandemic as the virus mutates.
Since the end of June, the delta variant has been the main version causing U.S. infections. As recently as the end of November, more than 99.5% of coronaviruses were delta, according to CDC data.
Scientists in Africa first sounded the alarm about omicron less than a month ago and on Nov. 26 the World Health Organization designated it as a “variant of concern." The mutant has since shown up in about 90 countries.
