US health authorities on Monday halved the recommended isolation time for people with asymptomatic COVID-19, as President Joe Biden warned Americans not to panic amid a surge of cases threatening wider social disruption.
Speaking about the rapidly spreading Omicron variant, Biden said some US hospitals could be "overrun," but the country is generally well prepared to meet the latest surge.
The coronavirus continued to punch holes in airlines' busy Christmas holiday schedules Monday, with multiple airlines saying spikes in cases of the Omicron variant have caused staffing shortages.
The CDC recommendations, which cut isolation for asymptomatic cases from 10 to five days, open the way for people to return to work sooner -- minimising the prospect of mass labour shortages in key parts of the economy.
The recommendations, which are non-binding but closely followed by US businesses and policymakers, further suggest that the five-day isolation period be "followed by five days of wearing a mask when around others."
The agency said the new guidelines were "motivated by science," which had demonstrated that the majority of COVID-19 transmission occurs early in the course of illness, generally one to two days prior to the onset of symptoms and in the two to three days after.
In a virtual meeting hosted by the White House with several state governors and top health advisors, Biden stressed the Omicron variant would not have the same impact as the initial outbreak of COVID-19 in 2020 or the Delta surge this year.
"Omicron is a source of concern, but it should not be a source of panic," he said.
Testing is more widely available and mass vaccinations mean that for many people infections do not lead to serious illness.
'More work to do'
With Omicron now the country's dominant strain, more than 200,000 daily cases were recorded over the past two days, quickly approaching records set last January.
Biden acknowledged that despite ramping up testing capacity, it's "clearly not enough."
"Seeing how tough it was for some folks to get a test this weekend shows that we have more work to do," he said.
In addition to expanding free testing sites, the administration will soon send 500 million at-home test kits to Americans, Biden said.
But "if we'd known, we would have gone harder, quicker," Biden said. "We have to do more."
The United States has recorded the world's highest national pandemic toll, with more than 816,000 recorded COVID deaths and 52 million cases.
International comparisons are skewed by differences in the accuracy of governments' reporting methods, while on a per capita basis the US death rate is further down the list.
Hampering the US response has been fierce political resistance to vaccines that were developed at record speed in 2020.
Many Republicans in particular are resisting the Biden administration's push to mandate the shots in large businesses. There has also been reluctance, again mostly in Republican circles, to get booster shots.
One pro-vaccine bastion is New York, where some of the toughest mandates in the country took effect Monday.
The rules, ordered by outgoing Democratic Mayor Bill de Blasio, require all private-sector employees to get vaccinated.
Proof of full vaccination is also required for anyone aged 12 and up to eat at indoor restaurants or enter other public venues, like gyms and movie theatres. Children aged five to 11 will have to show proof of one vaccine dose.
De Blasio called it a "historic day for New York City."
Despite the city-wide precautions, tech giant Apple restricted its New York stores to pick-up only services over the infection surge, closing its doors to browsers.
Touching on possible further mandates, lead White House medical advisor Anthony Fauci suggested a vaccine requirement for domestic air travel might be necessary.
"I think that's something that seriously should be considered," he told MSNBC.