The Government's approach in popping the travel bubble with all Australian states and extending Level 2 in Wellington is the appropriate level of caution for the Delta variant, Marc Daalder writes
ANALYSIS: It's a move that could easily be decried as overcautious, but the Government's decisions to shut off all quarantine-free travel from Australia and to extend the heightened state of alert in Wellington treats the risk of a Delta variant outbreak with the care it deserves.
There's a genuine possibility there are zero active cases of Covid-19 in the community in New Zealand, or in three other Australian states which have seen extensive travel from the Covid-19 hotspots of Sydney and a gold mine in the Northern Territory.
But the fact that the Covid-19 case that visited Wellington last weekend has since infected his wife shows he was at least able to transmit the virus. Whether he's part of the 20 to 30 percent of coronavirus cases that only pass the virus on to one other person or the 20 percent who make up as much as 80 percent of all transmission remains to be seen.
However, even a single case of the Delta variant that slips through the layers of social distancing and testing and contact tracing and isolation that have been imposed on Wellington and at the borders could spell the end of New Zealand's long streak without a serious outbreak. It was likely a single case that sparked Fiji's current epidemic - a roaring bonfire by almost any standard, including New Zealand's.
In fact, Fiji is now regularly reporting new daily cases in the triple digits. The most New Zealand ever identified, even at the height of our Level 4 lockdown in March and April, was 89. Given that more than 10 percent of the tests conducted in Fiji are coming back positive, there are likely to be far more undetected cases than even the record 304 cases reported on Thursday.
It took a stringent Level 4 lockdown with high compliance and a careful easing down the alert levels over the subsequent month-and-a-half for New Zealand to eliminate Covid-19 in the first place. And that was with the relatively formidable resources of our health system, police and public service to bear. The likelihood that Fiji can put a variant of the virus that is twice as transmissible back in its box is dwindling by the day - and despite the Government's protestations that it is too early to start talking about the virus becoming endemic there, the fact that ministers are even raising it in the first place is indicative enough.
This is not to say that New Zealand would necessarily fail to eliminate a Delta outbreak. But our ability to beat this variant of the virus is not a foregone conclusion, either.
It would likely necessitate a Level 4 lockdown. Back in August, Level 3 measures in Auckland were able to reduce transmission of the virus such that its reproduction number - the average number of people that each case infects - fell to 0.7. In other words, around 30 percent of the chains of transmission were eliminated with each new round of infection.
The same measures applied to an outbreak of the Delta variant would see a reproduction number of 1.5 - the number of new cases in each round of transmission rising by 50 percent. If you start with a small cluster of five cases, you'd be getting 288 new cases a week by the seventh week of transmission at Level 3.
This is the conclusion our expert virus modellers like Shaun Hendy have also come to.
"Because of the extra transmissibility, our Alert Level 3 might struggle to contain an outbreak," the Te Pūnaha Matatini director told Q&A on Sunday morning.
Now take a look at the situation we find ourselves in now. If Wellington steps down to Level 1 and we miss even a single case, the consequences could be dire. At Level 1, the reproduction number for the Delta variant would likely be above 4 - meaning each case transmits the virus to four other people. If we miss even a single case at Level 1, that could blossom into more than a thousand new cases within five weeks.
Given the complacency that has set in in recent weeks, there's a reasonable chance we could miss a case or two.
That complacency can be seen in the slump in QR code scans despite bubble pauses and outbreaks in Australia, or in the dreadfully low testing levels prior to Wellington's move to Level 2. Since that move, Covid-19 testing has surged. On Thursday, 3713 tests from Wellingtonians were processed - including as many as 1752 contacts of the Sydney case. However, that still leaves around 2000 people who got a test because they were symptomatic in Wellington alone.
Assuming there wasn't a sudden surge in people with cold and flu symptoms in Wellington this week, we should be seeing some 2000 tests a day from Wellington, plus many thousands more from elsewhere around the country. But on the previous Thursday, a total of 5246 tests were processed nationwide - and this includes regular testing of border workers. Clearly, thousands of New Zealanders are symptomatic on any given day but not getting tested.
It's this sort of complacency that allowed the Americold cluster to spread undetected for the better part of two weeks back in August. Remember, one of the cases in that cluster became symptomatic as early as July 31 but the first positive tests only came through on August 11, from a different family which had done the right thing and gotten a test when they developed symptoms.
New Zealand's success to-date has come from a mix of luck, compliance with restrictions and a healthy respect for the damage the virus could do. But luck isn't something you can rely on and complacency is increasingly eroding compliance, leaving only prudence and caution in our arsenal. In recent months, however, the Government has taken on more risk than it might have previously.
Look at Auckland leaving Level 3 after only three days in mid-February, only to have to jump back up the alert levels two weeks later. Or the delay in closing the border to New South Wales as more and more cases of the Delta variant were uncovered.
This latest scare in Wellington appears to have shocked the Government back into its tried-and-true risk-averseness. Officials are right to have faith in the efficacy of our contact tracing and testing systems, which have managed a number of minor outbreaks in the past, but the Delta variant is a whole new ballgame.
We don't have enough data to say for sure yet, but there are strong indicators that the variant is more likely to lead to severe health outcomes than the original coronavirus. It can also infect and spread from vaccinated people, although they fortunately appear to be spared from the higher risk of hospitalisation, severe illness and death.
With fewer than one in 10 New Zealanders vaccinated, our elimination status could be on the line. Given that, closing the borders to Australia as it tries to scope out the extent of its own outbreak and extending precautionary measures in Wellington are appropriate reactions to the danger of the Delta variant.
We should be treating this variant with the same caution we approached the original strain of the coronavirus back in March of 2020. We simply have too much to lose if we make the wrong call.
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