Very important question: Is it possible to eliminate COVID-19 and if so, how long it takes?

New simulations by @Agent_Jase & colleagues for AUS & NZ: It is possible and likely by mid-June!

Elimination probability under current restrictions

I am even more optimistic: thread.

First, let’s appreciate that eliminating COVID-19 is hard. Even when there are only a few cases, just one mini-outbreak could postpone elimination several weeks.
See the long tail of few cases in S. Korea.
https://www.worldometers.info/coronavirus/#countries

Australia & New Zealand have been very successful at controlling the epidemic. Eliminating the epidemic seems possible. The simulations suggest it is 90% likely by mid July.

But the simulations may actually be conservative. First, they assume a growth factor (R) of 2.2-2.7. In fact there is evidence it was never that high in Australia.
https://www.afr.com/policy/health-and-education/it-s-luck-that-has-saved-us-from-the-pandemic-20200420-p54lbg

Australia and New Zealand have low urban density and they had higher temperatures and higher UV exposures (Southern Hemisphere summer), factors which may credibly play a role. https://twitter.com/maksympolyakov/status/1253877379371540480

The simulations also do not take into account that some restrictions can be lifted in places where transmissions are limited. It seems that it can be the case in schools. Children seem less likely to become infected and transmit the disease. https://www.abc.net.au/news/2020-04-26/nsw-health-report-tracking-coronavirus-covid-19-cases-in-schools/12185582

Finally, the simulations do not take into account that restrictions can be lifted in states/regions where infections have disappeared with interstate/regional travel restrictions kept in place. https://twitter.com/rabeetourky/status/1249531548203773953

All these elements suggest elimination is 1) more likely than in the simulations, 2) not jeopardised by lifting targeted restrictions.

The consequence? If elimination is within reach, it is reasonable to aim for it, and to keep the required restrictions as long as possible.
End

Cc @jben0 @JohnQuiggin @RabeeTourky