The Australian Technical Advisory Group on Immunisation (ATAGI) loves a preference, and this single word “preferred” has driven much of the uncertainty around what any given individual should actually do.
ATAGI holds that AstraZeneca is not the preferred vaccine for people aged under 60, but a preference is not a directive. It’s not even a recommendation. It’s slightly stronger in meaning than the serving suggestion on the box of a Lean Cuisine.
ATAGI’s use of waffly language is deliberate. If we’re being generous then that makes sense because it is difficult to make strict prescriptions about the delivery of a new vaccine we’re still learning about in a dynamic setting where one’s risk of infection can change in a day. Also if one month’s firm, confident recommendation turns out to be incorrect, there won’t be much trust in the next recommendation.