Cost of rollout delays getting critical because of the way people think.
Take AZ now , and 2nd shot +12 weeks OR
Do nothing, because Pifzer hits the shops in September is the question.
So every day that passes from now on gives Joe Average a reason to 'ride it out/do nothing'. Maybe this is why hard delivery schedules are being suppressed. It is also probable that something else is needed for 12yo and up. This mucks up needed doses and percentages.
People vote with their feet(Old GP saying). People hear what they want to hear. Mrna vaccines are due to ramp up in September - well they better IF there is to be an October election and someone wants to take credit for this happy coincidence at the ballot box.
So to get AZ into arms, I think promotions will have to occur. At least Joe B has a target of 70%, but with the variants, scary cat Australia will probably go for 80%, yet Israel and Canada takeup is tanking below 70%, with the more popular soap-powder/product.
What we do need, is to alter that 80% vaccinated picture to '80% have have been offered the shot' , and then be open up, like the UK. I do not want to see the brakes applied because 35% failed to take action, and oh, we need to offer them 2nd, 3rd... final call rubbish.