Thread by @DrZoeHyde

At what level of vaccination can Australia safely reopen?

With 70% of adults vaccinated, expect:
📈 6.9 million cases
🏥 154,000 hospitalisations
☠️ 29,000 deaths

At 80%:
☠️ 25,000 deaths
🤒 270,000 people with long COVID

We need >90%, including children, to be safe.
#auspol

Children & adolescents must be included to reopen safely. If we don’t vaccinate them we can expect thousands of deaths from vaccine breakthrough infections.

Children also benefit directly from vaccination.

75% vaccination in children would prevent 12,000 child hospitalisations.

These figures are the results of new modelling produced by @GraftonQuentin, @Tom_Kompas, John Parslow, & me.

We explored what would happen when the final stage of the National Plan is reached, where it’s proposed to manage COVID-19 like flu.

Read more: policyforum.net/australia-cann…

Our results are broadly consistent with modelling from two other teams.

Researchers at the @BurnetInstitute predicted thousands of deaths if restrictions are eased before very high levels of vaccination are achieved.
burnet.edu.au/system/asset/f…

A recent @GrattanInst report suggested we should aim to vaccinate at least 80% of the total population before opening up.

The government’s target of 80% of those aged 16 years and older is actually only 64% of the total population.
grattan.edu.au/report/race-to…

The Grattan Institute found if we open up prematurely, even with 70% of people vaccinated, it would likely result in rapid, widespread community transmission that would overwhelm health systems.

When this happens, everyone suffers because routine healthcare may be unavailable.

Why are these findings different to the recent Doherty Institute modelling?

The Doherty Institute made some unrealistic assumptions. They assumed a low proportion of young people are symptomatic, and that children don’t transmit much, which is wrong.

https://twitter.com/drzoehyde/status/1336612124835995648?s=21

The Doherty Institute modelling was also limited to a 180 day horizon, and they assumed that testing and contact tracing measures would remain at least partially effective even at very high daily case numbers.

NSW is under significant pressure now.

https://twitter.com/trudymcintosh/status/1428204510971793417?s=21

Unfortunately, COVID-19 isn’t going away, and Australia does have to find a way to manage some degree of transmission in the community.

But the safest way to do this, is to achieve very high levels of vaccination (>90%) before we contemplate opening up.

Globally, Australia’s still in a very fortunate position. Our hands aren’t tied by the virus.

The choices we make now will shape the future of Australia for years, perhaps decades. The health & economic costs of opening prematurely are huge & irreversible.

Let’s get this right.

Addendum: What happens at higher levels of vaccination coverage?

With 90% of adults vaccinated, expect:
🏥 77,000 hospitalisations
☠️ 21,000 deaths

With 90% coverage in adults AND children and adolescents, this is reduced to:
🏥 31,000 hospitalisations
☠️ 10,000 deaths

We can further improve these outcomes by offering a third booster dose of an mRNA vaccine to everyone who received the AstraZeneca vaccine.

In our target vaccination scenario, if we achieved a 90% vaccination level INCLUDING children and adolescents, PLUS gave a mRNA booster to AstraZeneca recipients, we could still eventually expect:

🤒 40,000 long COVID cases
🏥 18,000 hospitalisations
☠️ 5,000 deaths

Vaccinating children and adolescents is necessary to minimise hospitalisations and deaths.

At the 90% vaccination level, including children and adolescents in the vaccination rollout prevents 46,000 hospitalisations and 11,000 deaths.

Children also directly benefit from vaccination.

When 90% of adults are vaccinated, but children and adolescents aren’t, 15,000 hospitalisations in children and adolescents are projected to occur.

But we can prevent almost all of the projected hospitalisations in children and adolescents if we achieve the following vaccination levels in these younger age groups.

70%: 12,000 hospitalisations 🏥 prevented
80%: 13,000 🏥 prevented
90%: 14,000 🏥 prevented

When calculating the number of expected hospitalisations and deaths, we used estimates of severity based on the original strain of SARS-CoV-2.

(We do, however, incorporate the much higher transmissibility of the delta variant into our work.)

Our calculations of expected outcomes are based on the original strain of SARS-CoV-2, because we don't yet know how much more severe the delta variant is.

But if we use preliminary estimates of increased severity, we project many more hospitalisations and deaths than shown here.

Our projections are therefore likely to be a lower bound of the outcomes that are expected to occur after reaching phase D of the Australian Government's National Plan (or if public health measures to control COVID-19 are abandoned sooner).

The take-home message:

🔑 Aim for a 90% vaccination target overall
🔑 Aim for 95% in vulnerable groups (e.g., older people, Aboriginal & Torres Strait Islander Australians)
🔑 Offer vaccination to BOTH children and adolescents
🔑 Offer a mRNA booster to AstraZeneca recipients

These are high targets, but we already achieve them in our routine childhood immunisation program.

In Australia, we achieve 95% immunisation coverage in 5 year olds.

We should set an equally high target for COVID-19.
health.gov.au/health-topics/…