The people of NSW appear disappointed with the apparent mind-changing and mixed messaging coming from our Health Department. (NSW to get Pfizer jabs booster shot, 22/6). But those who understand medical trials, and the sequential analysis undertaken, should be greatly reassured. These people know that rapid response to new results ensures the best evidence-based policy. While most research is conducted on small study numbers – slowly, over a matter of years – the pandemic has accelerated the generation of results from large numbers, which must be used to formulate an evolving standard of best practice. A responsive bureaucracy that changes policy on the best evidence must be praised, not derided. If they were too proud to admit potential error, we would have something to complain about. Alan Sexton, North Parramatta 23Jun2021.