Twenty days ago, the Omicron variant was not yet discovered in the United States; today it is every state except Oklahoma, Montana, Indiana, Vermont and South and North Dakota.

In New York, cases have increased by 75 per cent over the last week.

Joe Biden, president of the United States, is urging Americans to get vaccinated and those who have done so already, to take their booster jabs.

COVID hospitalisations have increased by 25 per cent over the last two weeks according to the U.S. Department of Health and Human Services data.

The World Health Organisation (WHO) is cautioning, “There are still limited data on the severity of Omicron. More data are needed to understand the severity profile and how severity is impacted by vaccination and pre-existing immunity. There are still limited available data and no peer-reviewed evidence on vaccine efficiency or effectiveness to date for Omicron.”

With winter now here, there is likely to be a surge in cases over the coming weeks which could spell further restrictions on movement and shuttering of businesses.

Many firms including Apple have had to pull back on workers returning to offices in light of this new outbreak.

According to the CDC, Omicron has jumped sevenfold in just seven days. What is concerning is the delta variant is still out there and influenza cases tend to rise during the winter months.

Both Pfizer and Moderna have developed an Omicron-specific COVID booster shot which should be ready for the public by February although Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said: “Our booster vaccine regimens work against Omicron. At this point, there is no need for a variant-specific booster.”

Asked whether he would advise people to travel, get together over the holidays or jump on a plane, Dr Fauci, who is also the White House Chief Medical Advisor said: “If you are vaccinated, your family is vaccinated, you have friends who are vaccinated – and hopefully also boosted – you can still enjoy a social gathering generally  in a home

“If I had to I would have no problem getting on an airplane. I’m vaccinated. I’m boosted. I know we have to wear a mask on an airplane.”