Researchers at the Royal Adelaide Hospital have begun recruiting volunteers for a possible COVID-19 vaccine trial later this year.

Volunteers are being recruited for a possible COVID-19 vaccine trial in Adelaide.

Researchers at the Royal Adelaide Hospital are looking for about 100 healthy adults for the trial which may be conducted later this year.

No particular vaccine candidate has been chosen so far, but SA Health says the recruitment campaign is about having a database of volunteers ready to go if a trial is authorised.

It's possible they could be called on to trial more than one possible vaccine.

"A number of vaccines are showing promising results in animal models so we are excited at the prospect of beginning human trials in Adelaide," clinical immunologist Pravin Hissaria said.

"By commencing the initial screening process now, we will be able to get started on the trial without any delay as soon as it has been finalised."

The call came as South Australia reported no new virus cases again on Monday, leaving the state's total on 440.

It also came as Premier Steven Marshall expressed concern at a surge in coronavirus cases in Victoria, which could impact on SA's decision to open all its borders on July 20.

Mr Marshall said local officials were "very hopeful" that Victoria would get on top of the current spike in infections and it was in the national interest for it to reduce the number of new cases.

"The entire country is on Victoria's side," he said.

But he said the events in Melbourne were worrying and when it came to SA's border restrictions, the decision would be based on what was best for public health.

"We are looking at the issue of borders very carefully and very closely at the moment," the premier said.

"We won't be opening our borders if it's not safe to do so."

On Tuesday, SA will send a team of contact tracing experts to Victoria to help quell the resurgence in COVID-19 cases.

Health Minister Stephen Wade said the three SA staff would spend three weeks there supporting local health officials.

"Victoria has had a significant surge and there have been more than 116 cases identified in the last seven days and 75 per cent of those have been the result of community transmission," Mr Wade said.

"It's very clear that as they continue to investigate those cases, they will need to get in early and to get in early you need to have the public health specialists who can interview the particular cases and trace their close contacts."