2021 Races at Risk - Australia/China/
It is reported the lead time for organizers to start setting up for the Australian GP requires a decision to race or not within the next 2 weeks. Australia has made some tough rule changes for covid that would make it difficult for F1 to open up the season there.
As of right now Australia is not reporting any vaccinations yet. They had a set back in their own vaccine development and had to cancel it during mid-trial. They would be at risk for their 3rd wave due to moving from summer to fall.