South Australia has opened another coronavirus vaccination clinic as authorities target 80 per cent of the state's population receiving their jabs by October.

South Australian authorities want 80 per cent of the state's population to be vaccinated against COVID-19 by the end of October.

The ambitious target was revealed on Monday as the state government opened a new vaccination clinic at the Women's and Children's Hospital in Adelaide.

People over 50 are now eligible to receive the AstraZeneca jab at community clinics, while GPs will be able to administer jabs from May 17.

Chief Public Health Officer Nicola Spurrier said it was critical for over-50s to get their first AstraZeneca dose as soon as possible given people are required to wait three months between doses.

She said the likelihood of SA meeting the 80 per cent target by October would depend on the state receiving an adequate and secure supply of vaccine doses.

"We are going to try as best as we can to get that vaccine out to everybody as quickly as possible. But obviously it's a logistical task that we've never had before," she told reporters.

"It's always good to have a target to aim for. Let's see how we go.

"Part of the responsibility obviously lies with us in SA Health but its also the public's responsibility to get in and roll up and get vaccinated."

A mass vaccination hub at the Adelaide Showground will start administering AstraZeneca jabs from next week and another two will open in the next month.

Health Minister Stephen Wade said he was pleased with the progress of the rollout.

"Our vaccination rate in South Australia is the highest of any mainland state," he said.

"Most South Australians will get their vaccinations through their GPs but these clinics are an important part of supporting that effort."

SA recorded three new coronavirus cases on Monday, all in hotel quarantine.