The society's initial call for the planned rollout of the vaccine to be delayed over its apparent efficacy, reported in Nine newspapers on Wednesday, was not based on breaking news and actually pre-empted more exact results likely to be released before the vaccine is widely deployed here.

According to a report published online by The Lancet on December 8, 2020, the vaccine was only 62.1 per cent effective at preventing disease when given in two standard doses. However, a small group of volunteers who had accidentally received a half dose and then a full dose recorded an efficacy rate of about 90 per cent.

"Trust and confidence in any COVID-19 vaccine will be crucial to its success," its authors wrote. "The appropriate pausing of the trial (in September 2020) to carefully investigate for safety concerns generated much publicity despite the reassuring outcomes of the safety review and trial recommencement... Further trials to substantiate the unexpected findings here and investigation of efficacy in older adults are now needed".

Those tests are now underway with results expected to be released in either February or March. Chief medical officer Paul Kelly moved swiftly on Wednesday to defuse criticisms of the vaccine and its planned rollout, including by some doctors, by telling Australians the AstraZeneca vaccine was completely effective in preventing serious illness and death from coronavirus.

"In terms of preventing death, it works 100 per cent of the time. In terms of preventing severe illness it works 100 per cent of the time. That's exactly the same as Pfizer on that interim information," he said.

"The great advantage of the AstraZeneca vaccine is it is being made here in Australia. It will be available as soon as the TGA gives its tick, which we expect that it will in February".

While well short of the 90 per cent plus efficacy rates recorded by Pfizer and Moderna, AstraZeneca's overall efficacy rate on the earlier testing of 70 per cent exceeds the World Health Organisation's minimum requirement. The society for immunology's position on the issue created confusion on Wednesday. It was reported that after initially saying it wanted a pause on plans to roll out the vaccine, it then changed its mind.

When asked why, its president, Professor Gilda Tachedjian, said: "One reason is we don't want to undermine the confidence in the vaccine. And we don't have the full picture. We need to go with the most effective vaccine so we can have herd immunity. But we just don't have the full picture at the moment".

It is unfortunate that view did not prevail before the original statement was made. While the suggestion authorities should wait to see what data AstraZeneca provides to demonstrate higher levels of efficacy was, in itself, eminently reasonable, and nobody disputes Australians are entitled to the best vaccines available, it was always a given any criticism of a specific product before final test results were in would be seized upon by anti-vaxxers and those wanting to politicise the immunisation program.

It is unfortunate the society has potentially compromised public confidence in a program of national importance that deserves a high level of bipartisan support.

A lack of willingness by the public to be inoculated could have a much more significant impact on the program's outcomes than any variations in efficacy rates.