The challenge
In late July 2021, for the first time since the start of the COVID-19 pandemic, New South Wales (NSW), Australia, was facing the gradual failure of lockdown and contact tracing to contain the growing wave of infections resulting from the Delta variant of the virus. To find new ways to stem transmission, NSW Health asked researchers at UNSW School of Population Health whether a targeted vaccination of younger adults in South-West and Western Sydney could turn the pandemic around and shorten the lockdown.
The solution
UNSW School of Population Health mathematical modelling expert, Associate Professor James Wood, provided NSW Health with a preliminary calculation that show the vaccination strategy was promising, but the insufficient vaccine supply at that time would make it hard to implement. NSW Health commissioned robust modelling to assess the vaccination strategy in local government areas in Sydney. The research showed that targeting vaccination would shrink and shorten the outbreak, bringing forward the end of lockdown by 2-3 weeks, and was led by A/Prof Wood in collaboration Professor Nick Golding from Curtin University, and other experts from UNSW School of Population Health, The Kirby Institute and University of Melbourne.
“NSW was the first jurisdiction internationally to intentionally target transmission through vaccination as a means to control a COVID wave – timely and effective partnerships between our expert modelling team and NSW Health made the difference.”
Associate Professor James Wood
The impact
In mid-August 2021, the Federal government purchased 1 million doses of the Pfizer vaccine. NSW obtained 500,000 of these vaccines and immediately implemented the vaccination strategy in 12 local government areas in Sydney with the highest rates of COVID-19 at the time. As a result, the number of COVID cases peaked in early September, making it possible to re-open from lockdown in the 2nd week of October.
Without the targeted vaccination intervention, it was expected that cases would grow 2-3 times more than they had, stretching resources in hospital intensive care units to their limits and as a result would have likely required extending lockdown into November that year. With lockdowns estimated to cost $1.3 billion per week, the successful targeted program likely prevented $2.5- 5 billion in losses to the NSW economy.
Led by A/Prof Wood, the UNSW modelling team has since provided continuous support and scenario projections to NSW Health post re-opening and through three waves of the Omicron subvariants. A/Prof Wood is also often quoted in media such as SMH and ABC.
