Vaccinate the young: Modelling backs strategy to slow virus spread

Vaccinating younger people is key to stopping the spread of the coronavirus around Australia with new modelling showing it would be the most effective strategy to slow down outbreaks.

Prime Minister Scott Morrison on Tuesday revealed the Doherty Institute’s modelling that national cabinet relied on to set Australia’s new pathway out of the COVID-19 pandemic, which has left multiple states in lockdown even 18 months after it began.

Treasurer Josh Frydenberg, COVID-19 Taskforce Commander Lieutenant-General John Frewen, Chief Medical Officer Professor Paul Kelly and Prime Minister Scott Morrison.Credit: Alex Ellinghausen

Professor Jodie McVernon from the Doherty Institute says the modelling shows that immunising younger people who tend to transmit the virus more – rather than older Australians who come into contact with fewer people – is a better strategy for the country to adopt from now on.

“So this is showing why at this point a strategic shift to targeting transmission and stopping these people getting exposed in the first place, can substantially improve outcomes,” Professor McVernon said.

Her charts predict much lower rates of symptomatic infections, ward admissions, ICU admissions and deaths if Australia adopts an “all adults” vaccination strategy compared to an “oldest first” strategy.

Under the national cabinet plan, revealed on Friday, vaccinated Australians will be able to avoid some lockdown restrictions when national and state vaccination rates get to 70 per cent. When the nation gets to 80 per cent, lockdowns won’t be necessary and international travel will be significantly increased.

“When you get it down to 80 per cent, the death, hospitalisation and infection rates are what you’d expect to see with something like the flu,” Mr Morrison told reporters.

National cabinet also took into account modelling from the Treasury, which looked at the direct cost of lockdowns. Treasurer Josh Frydenberg said the modelling backed the use of snap lockdowns to get on top of outbreaks of the Delta variant of the coronavirus.

“The economic costs comes down significantly if governments work quickly to get on top of the virus. Early interventions, short sharp lockdowns are the most cost effective way to handle the virus, particularly at the current time,” he said.

Mr Morrison had previously backed the NSW approach of using contact tracing to bring outbreaks under control without economically damaging restrictions, but the emergence of the Delta variant has led him to change his position.

The cost can be up to five times greater if the government doesn’t move fast, as states such as Victoria have recently, and lock down when cases emerge, Mr Frydenberg said.

He said higher vaccination rates will save hundreds of millions even if lockdowns are required.

“At 50 per cent vaccination rates, it’s costing the economy $570 million a week, at 60 per cent it’s cost $430 million a week. At a 70 per cent vaccination rate, its cost $200 million a week. At 80 per cent $140 million a week.”

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