South Australia has recorded another COVID-19 daily case increase, with 4274 new infections today.
The state also recorded five deaths, of people aged in their 50s to their 90s.
"We are obviously very sad with this number we need to report today," Premier Steven Marshall said.
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There are 164 people in hospital for COVID-19, which Mr Marshall stressed was "well within" the state's capacity to manage.
Of those, 16 are in intensive care, and two on ventilators.
Mr Marshall said about 80 per cent of intensive care patients seen in South Australia were unvaccinated.
Tests shot up by about 20 per cent, but Mr Marshall said most sites around the state still had short wait times and urged anybody with symptoms to queue up.
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The state announced yesterday a vaccine booster shot would become mandatory for aged care and disability workers, as well as healthcare workers.
Workers in those areas have until January 29 to comply.
Mr Marshall today warned the government was "very strongly considering" extending the booster mandate, especially to the childcare and education sectors.
Food shortages are also a worry for a state, with supermarkets battling supply chain issues around the country.
Mr Marshall said the issue wasn't "acute" in South Australia yet but the government was watching interstate events carefully.
"We want to stay ahead of the game," he said.
