Australians have been warned to prepare for a once-in-a-century pandemic with bans on gatherings of more than 100 people at pubs, clubs, churches and traditional Anzac Day services closed to the public.

Prime Minister Scott Morrison outlined the grim reality on Wednesday, after a marathon meeting of national cabinet.

It came NSW recorded its biggest single-day jump in coronavirus cases and a fifth death from the infection. The national toll is now six.

But Mr Morrison urged parents to keep their children in school, revealing his two daughters were not staying at home – because the expert advice was to leave schools open for now.

"Life is changing in Australia, as it is changing all around the world," he said.

"Life is going to continue to change, as we deal with the global coronavirus. This is a once-in-100-year-type event.

"We haven't seen this sort of thing in Australia since the end of the First World War. But together, we are up to this challenge."

Shopping centres, airports, universities and child-care facilities are exempt from the new rules, as are schools and public transport, which will remain open.

Correctional facilities, youth justice centres or other places of custody, courts or tribunal will also remain open.

But the Prime Minister cautioned that the effects of the coronavirus were likely to be felt in the community for six months of longer. Shutting down for a fortnight would not stop the virus, he said.

"We are going to keep Australia running. We are going to keep Australia functioning," he said.

"There is no short-term, quick fix to how this is dealt with in Australia. The idea that you can just turn everything off for two weeks and then turn it all back on again and it all goes away, that … is not our way through this."

Mr Morrison urged all Australians to remain a 1.5 metre distance from fellow citizens and practice common sense.

“If you’re getting in an Uber, sit in the back seat and not the front seat,” he said.

However, he urged parents to send their children to school.

“The health advice is that schools should remain open,” he said.

“As a father, I am happy for my kids to go to school.

“Whatever we have to do, we have to do for six months.”

Australia also upgraded its travel advice to to level four (do not travel) for every country in the world. It is the first time that level has been used.

“Do not go overseas – that is a very clear instruction,” the Prime Minister said.

“For those who are thinking of going overseas in the school holidays, don’t. Don’t go overseas.”

Mr Morrison announced that about 20,000 international student nurses who are already in Australia will be called on to help.

'Once-in-a-century': PM's grim warning for new travel, crowd bans_1
Smartraveller's updated world map – warning against travel to every country in the world. Photo: Smartraveller.gov.au
What the changes mean:
Domestic transport

Domestic air travel is still allowed but flights frequency has been reduced
Public transport is still allowed

Anzac Day

All public Anzac Day ceremonies have been cancelled
There will be a televised Anzac Day ceremony in Canberra

Aged care

Visitors or staff who fit any of the following criteria are banned:
Those who have returned from overseas in the past 14 days;
those who have been in contact with a confirmed case of COVID-19 in the past 14 days;
those with fever or symptoms of acute respiratory infection (cough, sore throat, runny nose, shortness of breath); and
those who have not been vaccinated against influenza (after May 1).

Universities

Will remain open. Academics and students are encouraged to work from home if possible

Community sport

Contact sports should be considered on a case-by-case basis
All codes should seek public health advice, and take into account mass-gathering issues

Travel restrictions

Australians told to not travel overseas
Australians overseas are advised to return home as soon as possible