Moderna Inc will supply Australia 25 million doses of its COVID-19 vaccine, of which 10 million doses against the original strain of the virus will be delivered this year, the drugmaker said on Wednesday.

Australia currently has two authorized vaccines from Pfizer-BioNTech and AstraZeneca.

It has been trying to speed up the rollout of jabs after it was stalled by supply hold-ups in Europe and concerns about blood clots tied to the AstraZeneca shot.

The deal also includes the supply of 15 million doses of Moderna's updated variant booster vaccine candidate to be delivered in 2022, the company said.

The pact with Moderna is subject to regulatory approval of its vaccine candidate, which is authorized for emergency use in individuals 18 years of age or older in the United States.

Moderna has also received authorization for its vaccine from health agencies including Canada, Israel, the European Union, the United Kingdom and Switzerland.