It sent confusion levels soaring.

And not just for patients. Left out of the loop, the AMA was among many to infer that a panicked government was usurping the Australian Technical Advisory Group on Immunisation and the clinical reservations of doctors.

Only a few weeks back, ATAGI advised that Pfizer was the "preferred" vaccine for under-60s, lifting it from the previous recommendation for over 50s. If its first age-based restriction, set on April 8, had not materially dented vaccine confidence, this second one was a hammer-blow.

It carried the implicit suggestion that the locally manufactured AstraZeneca vaccine presented a greater risk to under-60s than the super-transmissible Delta strain of the coronavirus running rampant in many countries, and on the loose here too.

In fact, ATAGI had always said AstraZeneca could be administered to under-40s where Pfizer was not available, the perceived danger of COVID-19 outweighed any statistical risk, and informed consent was given.

Another fact: the actual substantive aspect of the under-40s change, such as it was, was to give doctors more control over patient options, a Medicare consulting number, and professional indemnity where AstraZeneca is prescribed.

Had it been explained properly, this "encouragement" could have offered a faster up-ramp towards full community vaccination - surely a public good. That is now less likely, because the confusion and the war of words it provoked has likely exaggerated fears about AstraZeneca clotting right across the age spectrum.

But who knows? Change itself has become a barrier to take-up. That, and last year's failure to procure adequate supply of Pfizer - the truth that dare not speak its name within the government.

Health Minister Greg Hunt came close to acknowledging this on Tuesday, assuming you could follow him at all.

"Why now, two weeks later, are you advising people to talk to their doctors about going against that [ATAGI] advice ... have these decisions been forced by your inability to get adequate supply of the Pfizer vaccine to cover younger Australians, and you have an effective oversupply of AstraZeneca?" asked Seven's Mark Riley.

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"No," replied Hunt before skiting about the Coalition's brilliant foresight in ensuring "significant supplies of ... sovereign vaccine manufacturing here in Australia".

"The medical advice has not changed. There's simply a recognition that the access for those who wish to make an informed consent decision can be broadened, consistent with the supply."

Still confused? Job done. This was essentially a "yes", but buried in so much verbiage as to sound like more like a "no". And, of course, to be unusable for TV news.

In any event, the "recognition" of "access" and "supply" was known months ago, when the initial age distinction was introduced.

So if ATAGI's medical advice hasn't changed, what has? Answer: the politics. Amid the return of what might be called Covid reality - failures of hotel quarantine, lockdowns, disruption and fear, Morrison's "Team Australia" rhetoric has given over to toxic parochialism. National cabinet has become dysfunctional, merely another stage for renewed Commonwealth-state bickering.

Voters can see how leaderless this desultory vaccination program has become. Even some federal Liberals concede privately that it has been royally botched.

As public failures go, the vaccine rollout - and the refusal to plan dedicated quarantine facilities last year - may be the worst and most consequential of any federal government program.

And all with a supposed marketing man as Prime Minister.