An expert is calling on Kiwis to up their use of the COVID Tracer app, saying it will reduce the risk of shifting into lockdown if people test positive amid New Zealand's latest COVID-19 scare.
So far no locals have tested positive for the virus after an infected Australian tourist spent time in the city last weekend. It's assumed he has the highly infectious Delta variant.
The region is at alert level 2, which restricts gathering sizes to reduce the risk of a super-spreader event. It's estimated around 80 percent of all transmission comes from about 10 percent of cases.
"The Delta variant we know is actually about twice as infectious as the variant we were dealing with last year," University of Canterbury professor Michael Plank told Newshub.
"We've seen examples in Sydney, caught on CCTV footage, that the virus has actually spread from one person to another just as a result of them walking past each other in a mall. It can be spread in these really fleeting contacts."
Dr Plank is also a principal investigator at Te Pūnaha Matatini, whose work on modelling COVID-19 outbreaks has informed the Government's zero-tolerance response. He backed the move to level 2 for the capital, despite the short-term impact it's having on some businesses.
"The move to alert level 2 is definitely warranted. It's important to understand it's not really a lockdown - level 3 you might call a lockdown, but under level 2 most things still can be open, subject to those restrictions.
"It's a sort of middle ground that allows a lot of activity to continue, but it limits the potential for further spread - particularly by limiting gathering sizes, it reduces the risk of having superspreading events that could really allow the virus to spread very quickly."
If contact tracers can figure out who might have been exposed to the virus and get them tested and into isolation, the need for a tougher lockdown is reduced. However, tracers have to work backwards - and while tracking movements after an outbreak is important, it's vital for contact tracers that people have been scanning in beforehand so an outbreak can be nipped in the bud.
A week ago, just one in 15 adults were regularly scanning in, data showed. Scans typically pick up after a community case is reported - and that's happened again. Nearly twice as many scans were recorded on Wednesday - 894,288 - than on Monday.
"Making sure you scan in everywhere you go will give our contact tracers the best chance of catching up with this virus and getting ahead of it, and hopefully being able to control it without needing to go to a higher alert level," said Dr Plank.
COVID-19 Response Minister Chris Hipkins and Director-General of Health Ashley Bloomfield are due to give the latest update at 1pm.