The key lesson here – in my book – is the importance of our border with the outside world. All the recently identified local cases in NSW and Victoria stem from one breach of international quarantine in NSW.
Eliminating community transmission was and is a great thing, but this virus is sneaky and will get back in. The risk is higher when you have people arriving into quarantine from countries with high infection rates.
For example, there are 40,000 new notified cases per day in the UK. That might be 100,000 new true infections per day given inevitable under-reporting and asymptomatic cases.
Allow five days for symptoms to manifest and a quarter of infected people being asymptomatic but still able to infect someone else from – say – day six to 10, that is five times 100,000 plus 25 per cent of five times 100,000, which equals 625,000 people – or 1 per cent of the UK population who – unwittingly – might board a plane and bring the virus to Australia.
Of 300 people on a Dreamliner, we could expect three to be carrying the virus.
Quarantine at our international border is good, but it will, unfortunately, never be perfect. Witness the incursion into Sydney, then NSW, which has now spread to Victoria.
My rough guess is that somewhere in Australia we will see about one viral leakage per month out of international quarantine, and the last month has demonstrated how much disruption that can cause.
How do we tighten up our international border further? Ongoing “as best as possible” practice in quarantine of course. Constant quality control and learning to improve infection disease control is needed.
But what about the testing of people before they get on the plane? That will help, but still misses the people who are not yet shedding the virus.
The additional measure that I do not see being discussed, but which in my view should be, is prioritising that the first doses of a vaccine in Australia be administered to all staff in international quarantine, airport and airline staff and customs.
Why? Because it is likely (but not yet proven) that vaccination will not only stop severe disease, but also stop people getting infected in the first place. Thus, a security guard in quarantine will be less likely to unwittingly take the virus home to their family and the community.
This might reduce viral incursions out of international quarantine in Australia from something like one per month to one every four months or so. That is a major gain.
We need to seriously consider this first deployment of the vaccine. Perhaps urgently.
Back to what we have in front of us now in Victoria: it is precarious. The measures so far from Victoria’s Department of Health and Human Services, including reinstating masks and reducing the size of gatherings, are on the money.
Contact tracing, community testing and surveillance systems in Victoria now face their first major test after the second wave. The aspiration is the greatly enhanced capacity will stamp out the outbreak and get Victoria back to donuts.
But we need other proportionate measures to give contact tracing the best chance of stamping this out – without the need for a hard lockdown. Masks are back on, and group sizes in private homes reduced. What else should we do?
I wonder if we might blend some lessons from our second wave, with a bit of the NSW playbook. Remember our five-kilometre radius rule? The wide-ranging travel of so many citizens over the festive seasons has allowed the virus to hitch a ride to many new locales. We do not want to (yet) force people to stay within five kilometres of their home or holiday spot, but it is reasonable to ask everyone to think about reducing their movements as much as practicable. As per a NSW empowering-of-the-citizenry approach.
Come Monday, also expect that people going back to work will, wherever possible, not be going back to the office – but working from home. The new year is looking a lot like 2020 continued.
The next couple of days will set the scene for additional measures if required. Hopefully we can avoid a retreat to restrictions, but I fear we will need to tighten up again.
Tony Blakely, an epidemiologist and public health medicine specialist, is a professor at the University of Melbourne.