Daily coronavirus cases have fallen by as much as 44% in states across the Midwest and Upper Great Plains over the last two weeks after more governors institute mask mandates as infections soar in coastal states such as California and New York

Coronavirus cases have been stabilizing and steadily declining across the Midwest and Upper Great Plains over the last few weeks.

States such as Illinois, Nebraska, North Dakota, South Dakota, Wisconsin and Wyoming - some of which were hit the hardest by the virus - are seeing counts fall by as much as 44 percent.  

One reason for the drop appears to be that governors in several states, such as Iowa, North Dakota and Wyoming, finally instituted mask mandates after resisting for months.

Another is that a sizable percentage of the population in these states, at least 20 percent, has already been infected, meaning the number of new cases is likely going to decline, according to analysis from covid19-projections.com. 

Meanwhile, infections are surging in coastal states such as California and New York, reminiscent of the early days of the pandemic, although it's unclear why. 

It comes as the US COVID-19 death toll, which now stands at more than 292,000, surpassed the number of Americans who were killed during World War II.

The director of the Centers for Disease Control and Prevention , Dr Robert Redfield, also issued a stark warning on Thursday, saying daily death tolls over the next two to three months will likely exceed the total lives lost in the US during the 9/11 and Pearl Harbor attacks.  

New coronavirus cases have been declining across Midwestern states such Illinois and Wyoming. In Illinois, daily cases have declined by 15% over the last two weeks while, in Wisconsin, they've declined by 24%

In Wyoming, new infections have dropped by 32% over the last two weeks and, in North Dakota, they have decreased by 44% . Both states' governors recently instituted mask mandates after months of resisting 

New daily COVID-19 cases have declined by 16% in South Dakota and 19% in Nebraska . One analysis finds that, as more than 20% of the population has become infected in these states, the rate of new cases has decreased

In Illinois, 9,420 cases were recorded on Friday, which is a 15 percent decrease from the number of cases reported over the last two weeks, according to an analysis by The New York Times.

Hospitalizations and the average seven-day positivity rate are also on the downward, but officials warn that post-holiday surge is not over.

'We are not out of the Thanksgiving surge period yet,' Gov JB Pritzker said during a news conference on Thursday. 

'We unfortunately still have hundreds more Illinoisans in the hospital fighting COVID-19 than we did at our spring peak.'

Meanwhile, in nearby Wisconsin, COVID-19 infections have declined by around 24 percent with just 3,858 reported on Friday.

Despite being two weeks since Thanksgiving, which is also the standard incubation period for the virus, testing, cases and hospitalizations are dropping. 

'We're not seeing it in the case of a lot of new cases coming up,' Dr Jeff Pothof, Chief Quality Officer for UW Health, told Channel 3000.

'I don't know if it's just people are getting tested less and less often, or I don't know if it's a data issue where the broad availability of antigen tests are not filing into the databases that we're looking at.' 

In North Dakota and South Dakota, at one point the states with the two highest number of cases per capita, new cases have declined by 44 percent and 16 percent, respectively.

North Dakota's fall can be attributed to the actions take by Gov Doug Burgum , who was hesitant to impose any rules at the start of the pandemic.

Meanwhile, in coastal states such as New York cases are on the rise with more than 10,500 being recorded on Friday

The latest data from California shows that nearly 30,000 people are testing positive in a single day, although it's unclear why the number of cases are increasing

Burgum, who once opposed mask orders, extended on Wednesday a mandatory statewide mask mandate until January 18, noting the measures 'appear to be working.'

Restrictions on bars and restaurants and bars, including limiting capacity to 50 percent and 10pm closing time, will remain in place until January 8.  

Burgrum urged residents to keep wearing masks and social distancing, adding that North Dakota and the US are in 'the home stretch' with vaccines soon to be approved by the US Food and Drug Administration .

Cases in Wyoming have declined by 32 percent over the last 14 days, also believed to be due to stricter measures put in place by officials.

On Wednesday, a statewide order requiring that masks be worn in public places went into effect. It came one week after the majority of state counties instituted their own, reported the Casper Star-Tribune. 

On the same day, Rep Liz Cheney and the two GOP Sens John Barrasso and Mike Enzi released a joint statement expressing support for Gov Mark Gordon's mask mandate.

Dr Robert Redfield issued a stark warning on Thursday saying daily death tolls over the next two to three months would likely exceed the total American lives lost during the 9/11 and Pearl Harbor attacks. Pictured: Redfield gives remarks during a round table discussion at CDC headquarters, December 4

'It's not a cure-all, but wearing a mask and practicing social distancing goes a long way in stopping the spread,' the lawmakers said.

'These actions will help protect our family, friends and neighbors while still allowing us to keep our state open and working.' 

It comes on the heels of an FDA advisory committee recommending that the federal healthy agency approve the emergency use of the coronavirus vaccine developed by Pfizer Inc and its German partner BioNTech SE. 

Britain, Bahrain and Canada have already authorized the jab and the US is expected to do so by the end of the week, while a second jab, from Moderna Inc, is set to be approved next week.

Despite the latest moves to approve a vaccine, a top coronavirus adviser to President-elect Joe Biden delivered a stern holiday message to Americans - 'no Christmas parties' - and warned they face a COVID-19 siege for weeks to come. 

'The next three to six weeks at minimum... are our COVID weeks,' Dr Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, told CNN. 

'It won't end after that, but that is the period right now where we could have a surge upon a surge upon a surge.'   

Meanwhile, Redfield issued a stark warning yesterday saying daily death tolls over the next two to three months would likely exceed the total American lives lost during the 9/11 and Pearl Harbor attacks. 

'We are in the time-frame now that probably for the next 60 to 90 days we're going to have more deaths per day than we had at 9/11 or we had at Pearl Harbor,' he said during an event hosted by the Council on Foreign Relations event on Thursday.

'The reality is the vaccine approval this week is not going to really impact that, I think, to any degree for the next 60 days.'