By RNZ
As New Zealand moves closer to alert level 3, an epidemiologist warns this is not the time to be complacent.
Epidemiologist Professor Michael Baker told Morning Report the low figures of new cases have provided reassurance the country was ready to move down to alert level 3.
However, he warned that people should not be complacent about the rules if the "reproduction number" was to be under one. The reproduction number is the expected number of cases directly generated by one case.
"That's the idea that as a nation we have to keep this number under one, so that the average case infects less than one other, and that's really the core of sniffing out this virus."
There was a better chance of eliminating the virus if people adhered to strict rules, Prof Baker said, otherwise there was always a risk of seeing a spike of cases even under level 3.
He said New Zealand's cautious approach to coming out of the lockdown differed from overseas.
"Because all they're doing is suppressing the virus. When they come out of the lockdown, there's a lot of virus around and it will resurge quite violently in many countries, and that's not what New Zealand is doing.
"We're coming out of lockdown very cautiously on the basis that there won't be circulating virus by the end of this."
Any community transmission and outbreaks under level 3 would signal danger and require a swift response or risk going back to lockdown, he said.
In addition, limiting close contacts to reduce chances of transmission and continuing to treat level 3 like level 4 were key factors to avoid another lockdown, Prof Baker said.
People also needed to keep adapting hygienic practices as more returned to work over time, he said, and even consider wearing masks.
"Now more research is, I think, in support of [wearing masks], and remembering this is a different virus from ones we've seen before … I don't think we're quite ready for a national recommendation yet [for mass masking] but I think it should be close.
"The evidence is that people are quite infectious before they are aware that they are ill. We have to think about whether fabric will reduce the risk of you passing on that virus to other people just by talking and even breathing.
"We're looking at every opportunity to give us an edge over it, so the countries that are really succeeding against this virus are predominantly in Asia, and mask-wearing is common there."
Prof Baker said any policies on mass masking would need thorough development because "if they're used badly, they may be worse than not having a mask".
"I think it needs to on the policy agenda as an option, particularly as we're returning to more normal life, we need to have all of these barriers in place.
• Covid19.govt.nz: The Government's official Covid-19 advisory website
The flight was on its way to Auckland when it was forced to return to Christchurch.