Today’s case numbers are an increase on the 4408 infections reported on Wednesday, which was a rise of more than 700 cases from Tuesday. PCR testing also increased 5.7 per cent over the last 24 hours.

There are currently 231 people in hospital with COVID-19, down from 245 yesterday, with seven people in intensive care and one person on a ventilator.

SA Health said a man in his 70s passed away with the virus.

The rise in infections has been prompted by the Omicron BA.4 and BA.5 subvariants, which have the same severity as the previous BA.1 and BA.2 mutations but are considered more infectious and better able to evade immunity from vaccines.

The latest genome sequencing from SA Health, conducted last week, shows just under 55 per cent of test samples were BA.4 and BA.5 – up from 24 per cent the week before.

Chief public health officer Nicola Spurrier warned yesterday that the latest modelling from the University of Adelaide showed the state’s latest COVID wave was likely to hit its peak on Tuesday, July 19.

She said authorities were still uncertain about how high the peak would be, but previous modelling showed it could reach around 5000 cases.

Meanwhile, the Wayville mass vaccination clinic administered its last shot today before closing its doors at 2pm.

At its peak, the state’s largest COVID-19 vaccination hub administered 4000 shots a day.

Health Minister Chris Picton announced two weeks ago the state government would be shutting down the clinic, citing dwindling demand and health staff shortages.