South Australia's COVID-19 restrictions ease

South Australia has further eased COVID-19 restrictions, allowing home gatherings to increase from 10 to 50 and fitness classes to operate with one person per four square metres.

The changes, which came in at midnight, also allow hospitality venues to increase their capacity to 75 per cent outdoors and allow people to stand

From Monday, workplaces can go up to 50 per cent occupancy — a doubling of the current 25 per cent occupancy allowances that have been in place since January 27.

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"There are further gradual reductions in the restrictions," Premier Steven Marshall said yesterday.

"I've said right from day one, I don't want to have these restrictions in for one day longer than we need to."

The announcement of restrictions easing came after the state recorded 1639 new cases in the 24 hours to Thursday.

Mr Marshall said the rules were reviewed every fortnight and would be eased in stages, so long as cases did not skyrocket and the hospital system was able to cope.

Mr Marshall said the government was "very strongly recommending that people wear masks indoors now" when returning to work.

"This [Omicron] is still a highly transmissible variant," he said.

Seven people died with COVID-19 in South Australia in the 24 hours to Thursday.

On Thursday evening, the Australian Technical Advisory Group on Immunisation (ATAGI) updated its advice, saying Australians aged 16 and over would be considered "overdue" for a booster shot six months after receiving their second vaccine dose.

The federal government says the major change from the nation's vaccine experts, which it has accepted and referred to National Cabinet for state-by-state implementation, will not apply to international arrivals at the border.

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Federal Health Minister Greg Hunt said under the new advice from ATAGI, Australians would be considered "up-to-date" after receiving all the recommended vaccine doses for their age group.

Under existing recommendations, everyone aged 16 or over should get boosted three months after their primary course of shots.

The new advice goes a step further, stripping people of their "up-to-date" vaccination status and classifying them as "overdue" six months after their second shot.

The change is expected to be in place by the end of March.