The official reason is the (terrible) reality that a very small number, maybe one in a million, may die of blood clots. From a public health perspective, the death of a few in return for the life of millions is acceptable. The real problem - as pointed out by this column for months - is that there is another vaccine, with fewer "adverse circumstances" attributed to it, that is also available.

Additionally, there's been a resurgence in the UK - where AstraZeneca has been widely distributed. Perhaps it's not as effective as we hoped against new strains.

Who knows what made ATAGI decide to change its advice? Perhaps it was a concatenation, a string of circumstances that led to this change. Whatever. It's great to have it finally sorted out. It was logical.

The great thing about reasoning is that it not only provides you with the right answer, but also allows you to demonstrate exactly how it is you came to your (correct) conclusions. This makes it similarly easy to prove just why everyone else has got it so very wrong.

Unfortunately their failings probably had very little to do with this golden thread of logic. The problem nearly always resides at a deeper level. Everybody is way too busy embedding a stream of questionable assumptions into their original departure point. It's difficult to change after you've committed to a particular vaccine. Similarly, there are far too few common reference points in our society - particularly with the continued splintering of news services - to make what's "logical" for one the best result for everyone.

The result is that instead of moving towards a broad sense of agreement, communities are beginning to split apart long before they actually begin to consider the evidence in front of them. We now have the information to challenge, for example, health officials we believe may be providing advice that is not necessarily correct and take our own action. Bureaucrats called it "vaccine hesitancy"; we called it "intelligent awareness".

Previously we were all pretty much on the same page when we began analysing what was going on around us. Journalists would come to a more or less collective verdict of what was and wasn't ideal, but nevertheless seemed to work. Everyone would draw logical deductions from a similar point. Today that's not the case at all.

For many people, even the jumping off points - the "facts" on which analysis is based - appear based on premises they're not prepared to question. That's why good journalism is so crucial. It plays a vital role in questioning the hierarchy as it goes about making decisions for everybody. It's sometimes difficult, but always vital.

Anyway, must stop. I'm off to get my Pfizer.