The supply of coveted rapid antigen tests (RATs) appears to have improved dramatically in just the past week as retailers scramble to satisfy seemingly insatiable demand.

The latest crowd-sourced data compiled by Finder shows around 60 per cent of stores have stock, almost triple the level of a week ago.

In the private sector, millions of RATs are being shipped into Australia each week.

Also, the federal government said it has secured more than 80 million RATs for delivery in January and February while state and territory governments have placed orders for about 130 million RATs, with some already arriving in the country.

The surge in Omicron COVID-19 cases over the summer period sparked a national shortage of RATs amid chaos emerging from an overloaded PCR-testing system.

Although RATs have a lower accuracy than PCR COVID-19 tests, they have been recommended by state and federal health authorities as a preferable alternative to PCR tests to alleviate pressure on testing centres and laboratories.

However, health experts said the nation is collectively passing the Omicron peak, based on modelling and recent case and hospital admissions data.

"For most of the states, they indicated that the peak is going to be around about now to the next couple of weeks or so," Australian Medical Association vice-president Chris Moy told the ABC.

"It does vary a bit. [For] places, as I understand, that have sort of less restriction, the peak is going to be a bit later."

However, Dr Moy said, there was a lack of evidence about how long the plateau stage would last and whether case numbers would drop quickly, adding there would be a lag in the number of people being admitted to hospital and in ICUs.

Demand would remain strong, despite case numbers levelling

As more Australians are coming back to the workforce from the holiday period and students go back to school over the coming weeks, the demand for RATs is likely to remain strong.

However, it is still unclear exactly how many RATs Australians will need each week.

Deakin University epidemiology chair Catherine Bennett said that the demand for RATs depended on how people choose to use them.

"People will use them a lot initially and then ease off anyway, because they'll figure out when it actually makes a difference, when you need to know whether you could be positive and if you're asymptomatic," she told the ABC.

"So it varies, because they are used for so many different reasons, either screening, or testing if people aren't sure if they've got symptoms or not."

Professor Bennett said that, as new infection rates in the community started to ease, it would take off some demand pressure.

At the same time, RAT supply is expected to pick up significantly later this month and into February.

Prime Minister Scott Morison said on Thursday that national cabinet had not received medical advice recommending regular testing of teachers or students at school.

However, some states and territories may still put testing systems in place as national cabinet failed to reach an agreement on return-to-school rules.

Will RATs become the next COVID-19 glut?

The COVID-19 pandemic has seen some previously niche medical and hygiene products — such as hand sanitiser — explode in popularity, causing shortages and then excesses in supply as the market caught up.

Liquor distillers who stepped-up to produce hand sanitiser during a national shortage early in the pandemic were left with thousands of litres of surplus sanitiser they could not sell.

In some retail stores, hand sanitiser was even handed out for free.

The glut was also partially due to the easing of restrictions and a better understanding of how the virus transmits through the air more so than on surfaces.

Both Dr Moy and Professor Bennett said it was possible that a RAT glut could occur, but that this was better than the alternative and it was crucial for Australia to have a sufficient stockpile of the tests, especially for high-risk settings, such as aged and health care.

"Although PCR testing is something we can't underestimate as being extremely critical … if we're going to have any form of being able to live with COVID, as we put it, [RATs] are always going to be part of it," Dr Moy said.

There is one possible scenario that, once Australia has enough stock of existing RATs, they may not be sensitive nor accurate when it comes to testing against a future variant.

"It is a risk with new variants," Professor Bennett warned.

"You just don't know whether the tests will detect them, just as our immune system couldn't detect it as easily.

"So, having a bit of a glut is important because, when we go into winter … there will be more symptoms about, so people will want to understand whether it's a cold or it's COVID."