The omicron coronavirus variant has provoked fear and concern around the world. Here are answers to some questions about what is known — and isn’t known — about the variant.
What is omicron and why is there so much concern about it?
Where has omicron been found?
Has omicron arrived in the United States?
Are the current vaccines effective against omicron?
What is New York doing about the variant?
How have nations reacted to the variant?
What is the best way to prevent the emergence of variants?
