The State Government announced last month that third doses of the Pfizer vaccine would be available to everyone over the age of 18 from December 1.

To be eligible, the person must have received their second dose of the vaccine at least six months ago.

The Pfizer vaccine will be available as a booster dose to all patients even if they received the AstraZeneca vaccine for their first two shots.

Booster shots have already been available in SA Health-run clinics to frontline workers and aged care and disability residents who were in phase 1A of the vaccine rollout.

Health Minister Stephen Wade said a third shot would not be mandatory for those subject to a vaccination mandate, but emphasised the importance of booster shots to the vaccine program.

“I think it’s important to appreciate that two doses does give you good protection, especially against severe disease, but a booster will make sure your protection is both stronger and lasts longer,” he told ABC Radio this morning.

As of Monday, 80.1 per cent of South Australians over the age of 12 are fully vaccinated, while 89.3 per cent have received at least one dose.

The Australian Technical Advisory Group on Immunisation is currently examining whether to recommend booster shots be administered earlier than six months, in response to the Omicron variant.

The federal government has also flagged it will send out letters to every household in the country urging residents to come forward for their third shot.

More than 390,000 people across the country have received their booster shots since they became available, Health Minister Greg Hunt told reporters last Friday.