Those states include Minnesota, where a man is believed to have contracted the variant of COVID-19 during a visit last month to the Javits Center in Manhattan.
And now New York officials have revealed five other people in the NYC metro area have also tested positive for omicron.
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One is on Long Island, a 67-year-old Suffolk County woman who had just returned from South Africa.
The other four are in New York City. All of the cases are said to be mild.
As for that first case linked to NYC, the man from Minnesota, authorities say he was attending a massive anime convention between November 18 and 22.
Vaccination and masks were required - but the convention was packed, with more than 50,000 attendees.
"It honestly felt like normalcy," said attendee Anna Caroom. "Like, OMG maybe we're done! A lot of us go home to places where people aren't totally vaccinated, and that was more of the concern."
Officials are now urging caution and continued vigilance.
"We're assuming in New York City there is community spread at this point," said Mayor Bill de Blasio.
"This is not a cause for major alarm, because we do not have enough information," said NY Governor Kathy Hochul. "We aren't having shutdowns. We're not changing our protocols."
The governor also signed an executive order that goes into effect Friday.
It requires hospitals with bed capacity of less than 10% to forego elective surgeries until January 15 as COVID cases rise and some hospitals deal with staffing shortages.
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