Prime Minister Scott Morrison and Health Minister Greg Hunt (Image/Luis Ascui)

The "Commonwealth remit" for the vaccination rollout, to use the term employed by the Department of Health, consists of four groups: aged care residents, aged care workers, disability care residents and disability care workers.

Those groups formed the bulk of what the government in its vaccination rollout strategy called "Phase 1a". The remainder of Phase 1a consisted of quarantine and border workers, which the states and the Commonwealth jointly vaccinated, and front-line healthcare workers, which the states would vaccinate.

Those four groups in the Commonwealth remit totalled around 510,000 of the 680,000-strong Phase 1a. On February 15, Scott Morrison and Greg Hunt committed in a media release that "Phase 1a remains on track for first-round doses to be delivered within a six-week period".