Australians will be able to choose between two types of coronavirus boosters, after the medical regulator gave provisional approval to the Moderna vaccine to be used as a top-up dose.

The Therapeutic Goods Administration has given the green light for people 18 and over to get a Moderna booster shot, six months after their second vaccine dose.

The administration said on Wednesday Moderna would be able to be used as a booster regardless of what COVID-19 vaccine brand people received during their first two doses.

It came after the Pfizer vaccine was also approved as a booster shot.

More than 500,000 Australians have received their third vaccine dose since the boosters were made available.

The TGA said the Moderna booster was approved following the evaluation of safety and efficacy data.

-AAP