Assessing the impact of Australia’s mass vaccination campaigns over the Delta and Omicron outbreaks

Abstract

Background The Australian Government implemented a national vaccination campaign against COVID-19 beginning February 22, 2021. The roll-out was criticised for being delayed relative to many high-income countries, but high levels of vaccination coverage were belatedly achieved. The large-scale Omicron outbreak in January 2022 resulted in a massive number of cases and deaths, although mortality would have been far higher if not for vigorous efforts to rapidly vaccinate the entire population. The impact of the vaccination coverage was assessed over this extended period. Methods We considered NSW, as the Australian jurisdiction with the highest quality data for our purposes and which still refle..