NEW YORK • The surge in new Covid-19 infections is driving a fresh wave of restrictions in cities and counties across the United States.

California's "emergency brake", Oregon's "freeze", Philadelphia's "safer at home" and Minnesota's "dial back" are among a new patchwork of rules adopted that are much less strict and far more narrow than measures imposed to stop the spread of the virus in the spring.

However, the Trump administration does not support another lockdown or school closures, Vice-President Mike Pence said on Thursday during a coronavirus task force briefing, in which he also highlighted rising positivity rates for coronavirus tests administered across the country.

The number of patients hospitalised with Covid-19 in the US has jumped nearly 50 per cent in the last two weeks as Americans face a potentially grim winter and holiday season.

Nearly 79,000 people were being treated for the disease in hospitals across the country on Thursday, a Reuters tally showed, the most at any time during the pandemic.

Health officials have warned that the sharp rise in hospitalisations could worsen if Americans do not limit their Thanksgiving holiday celebrations to small, single-household gatherings.

The US Centres for Disease Control and Prevention issued a "strong recommendation" on Thursday that Americans refrain from travelling for the holiday, which will be celebrated next Thursday.

California's governor on Thursday imposed a curfew on social gatherings and other non-essential activities in one of the most intrusive of the restrictions being ordered across the country.

The stay-at-home order will go into effect from 10pm until 5am each day - starting tonight and ending on the morning of Dec 21 - and it will cover 41 of California's 58 counties and the vast majority of its population, said Governor Gavin Newsom.

"The virus is spreading at a pace we haven't seen since the start of this pandemic, and the next several days and weeks will be critical to stop the surge," Mr Newsom, a Democrat, said in a statement announcing the measure a week before the Thanksgiving holiday.

In California, the restriction essentially marks a return to the first-in-the-nation, statewide stay-home order that Mr Newsom imposed in March, except it applies only during the designated curfew hours rather than round the clock.

A similar 10pm-to-5am curfew order was issued on Thursday in Ohio and will remain in effect for the next 21 days, Governor Mike DeWine, a Republican, announced separately.

As in California, the Ohio curfew would not prohibit grocery stores from remaining open past 10pm, or keep restaurants from staying open late for takeout orders. Individuals would likewise be permitted to venture out for food, medical care or other necessities, as well as to take a jog or walk a dog.

Rhode Island Governor Gina Raimondo on Thursday announced a two-week "pause" period starting Nov 30 that will halt in-person college classes, close bars and limit capacity at restaurants and houses of worship.

Officials in Oregon closed offices to the public and are limiting the number of people in grocery stores at a time.

Michigan began a three-week shutdown on Wednesday that closed gyms, high schools, colleges and entertainment venues.

Minnesota, one of several Midwest states dogged by soaring infection rates per capita, ordered a shutdown of restaurants, bars, fitness centres and entertainment venues from yesterday until at least Dec 18, as the state's hospital intensive care units are stretched to capacity.

In the nation's capital, Washington DC, the Smithsonian Institution announced it would close its museums and the National Zoo beginning next Monday, with no set reopening date.

In Maryland, which reported a record 2,910 new cases in a 24-hour period on Thursday, the Baltimore public school district said it would halt in-person learning the week after Thanksgiving to avoid exacerbating the virus spread that may occur over the holiday.

Looking further ahead, Pennsylvania officials announced that crowds will not be permitted to attend annual Groundhog Day festivities in Punxsutawney.

Meanwhile, New York City's public school system, the nation's largest, halted in-class instruction due to rising infection rates just weeks after allowing its 1.1 million students back into classrooms on a part-time basis.

REUTERS, NYTIMES