I think vaccine approval is going to be earlier than you thought, especially when tonight's budget has assumed a vaccine is available in 2021, as well as Greg Hunt and various ministers have been openly optimistic about a vaccine early next year.
My worry about Australia is that if we only have 1 or 2 vaccine ordered, it will be too slow for those who want to be vaccinated in the population to be vaccinated. I think the strategies by other governments, such as Canada where they snap up a number of vaccines early is a better strategy.
With borders, I think the strategy is to delay an uncontrolled outbreak as late as possible so that when we open our borders and there's an outbreak, there would already been vaccine and/or cure available which only those who refuses one will be badly affected.
We cannot close our borders until the virus is completely eliminated from the world, as it will take a very long time which will significantly harm the country's economy and we will see a lot of people out of jobs already.