CSL Ltd said on Thursday it does not have the capacity to simultaneously produce AstraZeneca and Novavax Inc's COVID-19 vaccines after a local report said the US-based firm was looking for an Australian manufacturing partner.

Australian biotech CSL is already under contract to locally make 50 million doses of the AstraZeneca vaccine, and is currently churning out more than a million doses a week.

Australia is relying on deliveries from Pfizer after restricting the use of AstraZeneca's shot in April in people below 50 years due to rare blood-clotting cases.

In January, the government ordered 51 million doses of Novavax's vaccine, with the Therapeutic Goods Administration (TGA) allowing the company to apply for provisional registration of the shot.

Novavax has delayed its timeline for ramping up COVID-19 vaccine production, saying it does not expect to seek regulatory authorization for the shot in the United States, Britain and Europe until the third quarter of 2021.

In an interview with the Sydney Morning Herald, Novavax's chief commercial officer, John Trizzino, said his company was looking for a local partner to make its vaccines and has had early conversations.

Novavax did not immediately respond to a Reuters request for comment on its local production plans and who they have been in talks with.

"At this time CSL does not have the capacity to simultaneously manufacture both the AstraZeneca and Novavax vaccines," a spokeswoman said in response to emailed questions by Reuters.

"We remain fully focused on production of the AstraZeneca vaccine," the spokeswoman said, adding that CSL welcomes "discussions with governments as to how we can support Australia's ongoing vaccination needs.