Coronavirus: Expert says it's time to reform alert levels based on what we've learned

One of the country's top epidemiologists has called for a revamp of the alert system, based on what we've learned over the past year, saying it could prevent future lockdowns.

The current four-stage alert system was introduced on March 21, just a few days before the entire country was put into a level 4 lockdown.

Since then we've gone up and down the levels in response to new outbreaks - Auckland having gone as high as level 3 on three different occasions. 

But in addition to each of the levels having been tweaked since March last year, there have been times when extra restrictions and guidelines have been put in place, resulting in levels like '2.5' and '1.5'. 

University of Otago infectious diseases expert Michael Baker says it's time to overhaul the alert system. 

"We're a year into managing the pandemic. The alert system served us very well for the first major outbreak, and it helped us to stamp out the virus in seven weeks very effectively - we came out into a virus-free country," he told Newshub.

"A year later I think we could use it in a much more targeted way. We're using it in different geographic areas... we need to incorporate what we know about how the virus is transmitted indoors and that masks are very effective at stopping that transmission... It looks like it's time to really refine it."

We already have an effective seven-level system, he said - the four formal levels, 1.5 and 2.5, and level zero - normality, with the borders open. 

"We're suggesting that we do a lot more work to refine those levels below level 3 so we can use them in a more targeted way that involves far less disruption and getting people back to schools and work more quickly," Dr Baker said.

"Potentially using masks a lot more in indoor environments and also thinking about what indoor environments are particularly risky for transmitting the virus - and we know what they are."

Research has shown gyms, restaurants, cafes, hotels and places of worship are particularly risky places, linked to superspreader events in the US - particularly when masks aren't worn.

michael baker
Michael Baker. Photo credit: Newshub.

While masks offer some protection against contracting the virus to the wearer, their biggest benefit is stopping people who are asymptomatic - and might not realise they have the virus - from spreading it to others. 

"It's really just taking the scientific knowledge we've got about this virus over the last year, and using it to fine-tune the alert level system," said Dr Baker. 

Auckland's current alert level 3 restrictions end on Sunday morning, fingers crossed. Dr Baker said moving to level 3 wasn't an overreaction, but the lack of any community cases in the past week means it should be safe to move to level 2.

"We're not seeing cases that can't be explained, and if we get some more cases they're likely to be connected with known cases, and that means they should be manageable with the contact-tracing system... It's possible we could see some more cases over the next few days, but at this point all the indicators are very positive."

In hindsight, he says the move to level 3 "may not have been necessary" - but contact tracers are always working backwards, so when the first cases were discovered there was always the chance of a wider outbreak.

"We went to alert level 3 when we didn't really understand the source of the new case that was discovered last weekend," University of Auckland disease modeller Shaun Hendy told RNZ. 

"Over the course of the week I think we've got a handle on that cluster, and especially with the very high testing rates that we've had this week, that will give them some confidence that the cluster is contained and that they do have the right people isolated."

The rest of the country will move to level 1.