The long shot: delays, uncertainty and confusion in Australiaâs vaccine rollout Weâre sorry, this service is currently unavailable. Please try again later. Dismiss Save Normal text size Advertisement At 7.20pm on Thursday, a stony-faced Prime Minister walked into the blue room at Parliament House flanked by the Health Minister and the countryâs top health officials. AstraZeneca, long touted as the workhorse of the vaccine rollout, was no longer the preferred choice for those aged under 50. Just 15 minutes before facing the handful of journalists still in Parliament, the government had received advice from the Australian Technical Advisory Group on Immunisation that the vaccine rollout plan would have to be drastically changed.