What you need to know about COVID-19 today, Friday January 8.

National Cabinet announces new regulations for flights, international travellers.

Passengers on all domestic and international flights must wear masks and people from the United Kingdom will be subject to testing for the new strain of coronavirus before they board flights home, National Cabinet has decided.

Speaking to media following the meeting, Prime Minister Scott Morrison said mask wearing would now be mandatory for all domestic flights, except for children under 12 and those with an accepted exemption.

Masks will also be mandatory in all domestic airports.

"These measures, over the course of the next week, and the compliance arrangements that sit around that, will be put in place by the Commonwealth and the state governments," Morrison said.

International arrivals will be reduced by 50 per cent till February 15 in New South Wales, Western Australia and Queensland.

International air crew must undergo a COVID-19 test in Australia every seven days or on arrival.

Morrison said travellers to Australia must also return a negative COVID-19 test prior to departure.

Greater Brisbane to enter three-day lockdown.

Greater Brisbane will enter a three-day lockdown in an attempt to stop the spread of the highly infectious UK COVID-19 variant, Premier Annastacia Palaszczuk announced on Friday.

From 6pm Friday to 6pm Monday, all residents living in the council areas of Brisbane, Logan, Ipswich, Moreton and Redlands will be subject to stay-at-home orders.

It comes after Australia recorded its first community case of the more infectious UK strain of the coronavirus outside of returned overseas travellers in a Brisbane hotel quarantine cleaner.

COVID-19 update with Premier Annastacia Palaszczuk and Chief Health Officer Dr Jeannette Young. #covid19au https://t.co/VukOLkaJJK

— Annastacia Palaszczuk (@AnnastaciaMP) January 7, 2021

The mutated strain plaguing the UK is believed to be up to 70 per cent more infectious than the original.

Palaszczuk said the weekend lockdown was a preventative measure, to stop any potential spread early.

"If we do not do this now, it could end up being a 30-day lockdown," she said.

The Premier said residents could leave home for four essential reasons: to go to essential work, to provide healthcare and support for a vulnerable person, for essential shopping and for exercise. Two visitors will be allowed in homes. 

"I know this will be tough on businesses over the next few days but I am thinking about your long-term futures as well," Palaszczuk said.

"It is going to be tough on everyone for these three days, but I think everybody in Queensland, especially in that greater Brisbane area, knows that what we are seeing in the UK at the moment and other places around the world is high rates of infection from this particular strain, and we do not want to see that happening here in our great state, and that is why we are taking those strong actions today."

Although lockdown doesn't begin until 6pm TONIGHT, QLD Police are urging people not to go out and about today unnecessarily.

— 10 News First Queensland (@10NewsFirstQLD) January 7, 2021

The state also mandated masks, with Brisbane residents required to wear them when leaving home.

Queensland Chief Health Officer Dr Jeannette Young said the three days was a 'pause', to allow contact tracers to determine every possible case related to the cleaner.

So far, 79 people have been placed into isolation due to contact with the woman. 

"We need to act really, really fast. We need to find every single case now. We need to find every person who might have had contact with that lady now; find them, and get them into quarantine, and that's what we have got to do over the next three days. And I have absolute confidence that we will do that," Dr Young said.

"Until we have found all those people, we can't relax... I need people to be at home so we can contact trace them, so we can get them to go into quarantine in their home for 14 days, so we can test them, and quarantine them and test them, and quarantine them and test them again. That's absolutely critical."

The cleaner from Algester travelled on the public rail network to and from Brisbane's inner city and southside. 

Health authorities say she visited several locations while potentially infectious including Woolworths at the Calamvale Central Shopping Centre on Sunday January 3, Coles in Sunnybank Hills on January 5 and a newsagent at Sunnybank Hills Shopping Town on the same day.

Residents of Algester, Sunnybank Hills and Calamvale who have symptoms of the infection are especially urged to get tested as soon as possible.

Prime Minister Scott Morrison said Queensland had made a "very wise decision".

"I know they will be some in Brisbane today asking 'why is this necessary? There is only one case,'" he said.

"Well, this isn't any ordinary case. This is a very special case and one that requires us to treat things quite differently until we know more and we will learn much in the next few days.

"What Queenslanders will be doing over the next few days, they will be doing not just for themselves and their own communities, but for the rest of the country."

Wise call by Qld Premier @AnnastaciaMP to have a brief lockdown to enable Queensland health authorities to get on top of the UK strain case in Brisbane.

A big thanks in advance to everyone in greater Brisbane for their patience in coming days.

This will buy much needed time.

— Scott Morrison (@ScottMorrisonMP) January 7, 2021

Morrison said Greater Brisbane has been declared a hotspot on a 'Commonwealth level'.

"Our message to Australians who are in those areas is - stay where you are. Don't go anywhere. Don't go home to another state or any other part of your state," he said.

"Over the next few days, stay where you are. If you're somewhere else and you are planning to go there, don't. If you are from any of those places and you are somewhere else, you may be here in the ACT, you may be in Western Australia, you may be in Victoria - you should treat yourself as if you are in those places. You should get tested. You should monitor your symptoms."

Western Australia has reimplemented its hard border with Queensland, in effect from midnight.

Anyone who arrives in Tasmania from today who has been in the Greater Brisbane area since January 2 must immediately quarantine for up to 14 days.

The Northern Territory has declared the Greater Brisbane region a hotspot, meaning anyone arriving in NT today from these regions will have to return to Brisbane or enter mandatory two-week quarantine.

South Australia will require anyone that enters from Greater Brisbane to receive day one, five and 12 testing. Anyone who has entered SA from the area since January 2 must get tested.

NSW records 11 new COVID-19 cases, Northern Beaches lockdown to end.

NSW has recorded four locally acquired cases and seven in hotel quarantine on Friday.

Of the local cases, two are linked to the Berala cluster, one is linked to the Croydon cluster and the other infection, initially reported yesterday, is linked to the Avalon cluster but remains under investigation.

NSW recorded four new locally acquired cases of COVID-19 in the 24 hours to 8pm last night. One of these cases, from the Northern Beaches, was first reported yesterday morning but is included in today’s numbers. pic.twitter.com/jHIIOfQ8L0

— NSW Health (@NSWHealth) January 8, 2021

A total of 26,112 tests were completed in the 24 hours to 8pm Thursday.

Chief Health Officer Dr Kerry Chant said fragments of the virus had been detected in a sewage treatment plant at Ulladulla on the NSW South Coast for the first time.

This catchment takes sewage from Narrawallee, Milton, Mollymook Beach, Ulladulla, Kings Point, Burrill Lake, Dolphin Point, Lake Tabourie.

Dr Chant asked for anyone who lives in the area, or who had visited the area in the last week, to get tested.

Acting Premier John Barilaro said NSW would not close its border to Queensland, but anyone in the state who had been in Greater Brisbane since January 2 must self-isolate until 7pm on Monday, January 11.

Health Minister Brad Hazzard said the northern part of the Northern Beaches will emerge from its stay-at-home order on 12.01am Sunday, and will become part of Greater Sydney for the purpose of restrictions.

This is despite the new case linked to Avalon being under investigation.

Hazzard said he had "some reservations" about lifting the lockdown and urged people with COVID-19 symptoms in the area to continue getting tested in large numbers.

Mutant strain detected in Victoria's second wave.

A mutant strain of COVID-19 was detected in Victoria's deadly second wave.

One of the viruses that escaped hotel quarantine mid-2020 during Victoria’s second wave was a mutant precursor of Britain's new viral variant. #covid19 https://t.co/aUHTQK4ctH

— The Age (@theage) January 7, 2021

The strain is believed to have been a precursor to the highly infectious mutation now rampant throughout the UK, and has only been revealed now.

It infected at least 37 people in Victoria before the state's hard lockdown stopped the spread.

"We did not want to spook people that we had a real problem with mutants here," Professor Damian Purcell, the head of the molecular virology laboratory at the Doherty Institute for Infection and Immunity in Melbourne, told The Age.

"We expect to see them. They are going to keep coming."

Victoria recorded zero locally acquired cases on Friday, for the second day in a row. 

There was one new case in hotel quarantine.

Record COVID-19 deaths in US amid violence.

The US has registered more COVID-19 deaths in a single day than ever before - nearly 3900 - on the very day the mob attack on the Capitol laid bare some of the same, deep political divisions that have hampered the battle against the pandemic.

The virus is surging in several states, with California hit particularly hard, reporting on Thursday a record two-day total of 1042 coronavirus deaths. Skyrocketing caseloads there are threatening to force hospitals to ration care and essentially decide who lives and who dies.

#BREAKING: US sets new record for daily COVID-19 deaths with over 3,800 fatalities https://t.co/UDF4qvBCjS pic.twitter.com/RPGXifwGkE

— The Hill (@thehill) January 7, 2021

"Folks are gasping for breath. Folks look like they're drowning when they are in bed right in front of us," said Dr. Jeffrey Chien, an emergency room physician at Santa Clara Valley Regional Medical Center, urging people to do their part to help slow the spread.

"I'm begging everyone to help us out because we aren't the front line. We're the last line."

About 1.9 million people around the world have died of the coronavirus, more than 360,000 in the US alone. December was by far the nation's deadliest month yet, and health experts are warning that January could be more terrible still because of family gatherings and travel over the holidays.

A new, more contagious variant of the virus is spreading around the globe and in the US. It also remains to be seen what effect the thousands of supporters of President Donald Trump who converged this week in Washington, many of them without masks, will have on the spread.

Protesters break into the U.S. Capitol. Image: Getty.

Trump has long downplayed the virus and scorned masks, and many of his ardent supporters have followed his example. He has also raged against lockdowns and egged on protesters objecting to restrictions in states such as Michigan, where armed supporters invaded the statehouse last spring.

Australian GP will be postponed.

The Australian Grand Prix will be postponed to the back end of the Formula One season with Bahrain replacing it as the opening race in March, according to Aston Martin team owner Lawrence Stroll.

The move, due to the COVID-19 pandemic and quarantine restrictions, has been widely flagged in the media but is still yet to be confirmed by Formula One or local organisers.

"Melbourne has been - it's not officially announced but it will be - not cancelled but postponed. We will go there sometime in the fall (autumn) and the first race will be Bahrain," said the Canadian billionaire.

Formula One teams agreed the change in a virtual meeting with Formula One's new chief executive Stefano Domenicali on Monday.

-With AAP.

Feature image: Getty.