The initial vaccine doses destined for Australia were diverted to more urgent areas (which was the right thing to do). Then as domestic product of AZ ramped up, a scare campaign ramped up (media love to make people worried) and the body for recommending vaccines gave advice for under 50s to not take AZ (whilst there was no actual alternative). Because covid lockdowns were effective, and Australians were seeing such low rates, there was complacency amongst the population and they were willing to wait for their vaccine of choice. Now delta is looking like it is making lockdowns less effective, and there is ample supply of Pfizer, people are scrambling to get vaccinated.
I wouldn't give all the credit to the government for the low infection rate last year. I think it was mostly fear and reaction of people. e.g. by the time government started ordering restrictions, most companies had already switched to fully remote. Toilet papers were already gone from the supermarket shelves. People were already bunkering down. Then in a few weeks the infection peaked, and 2 months later students were back in school.
Since that initial success, the state governments improved their contact tracing process, which was successful to eliminate outbreaks every now and then, while things were mainly normal for most the year (except overseas travel).
Unfortunately, in late June this year, the Delta variant arrived to Sydney, and it proved impossible to control. The world-class contact-tracing process failed to stop the infection rate. So we are still in lock-down, with cases still increasing over a 1000 per day in the state (NSW).
However, other states in Australia are still enjoying full freedom. Probably, because they do snap lock-downs (3 to 7 days) whenever a case appears in the community.
Vaccination, the federal government put most of their eggs in one basket. It planned to produce and use the AZ vaccine, but the AZ blood clot issues, derailed their plans. So they stopped or limited AZ, and went begging for Pfizer doses. They are struggling to get enough of this, so they can acchieve 80% rate, to start re-openning the states currently in lock-down.
There might be plenty of vaccines in US and Europe, but unfortunately the rest of world can't get enough of it.
I can understand the initial delay in vaccination in AU & NZ, because given the scarcity of vaccines, and the high death rates in other countries, it would preferable the vaccines were given to those countries first.
Several zip codes in the Bay are at what... 98% vaccination rate? I still don't get how the "much better" governments of Australia and New Zealands, held as examples through the pandemic, couldn't match the vaccine rollout of... the Trump Administration.