In the past few days, Australia’s vaccine rollout has staggered from overconfidence to overcaution. Just weeks ago, the Morrison government was talking about having 4 million Australians vaccinated by the end of March, a figure that looked more and more as if it had been plucked out of thin air the closer that the date got.

Now the vanishingly small risk of blood clots caused by the AstraZeneca vaccine – perhaps one chance in a million of actually dying – has restricted its recommended use to Australians aged over 50, who are less vulnerable to the side effect.