ANALYSIS
Having previously dismissed the idea, Prime Minister Jacinda Ardern conceded on Friday that the new traffic light system effectively created two classes of people - the vaccinated and the unvaccinated.
Whether this is warranted depends on whether you think the ends justify the means.
Ardern could have decided to allow the same freedoms to all Kiwis under the new system, but she believes that would be too much of a burden on the vaccinated.
Instead the unvaccinated, if there is increasing community transmission, will face level 3-type restrictions on gatherings and hospitality venues, while businesses using vaccine certificates will have far more freedom to operate.
But Ardern said it's not just about an incentive to get vaccinated, or certainty for businesses.
"People who have been vaccinated will want to know that they're around other vaccinated people," she told the Herald on Friday.
"It is a way that we can give confidence to those who are going back into hospitality or to events, the confidence that we're doing everything we can to keep them safe and that they can come back out and start enjoying those things safely."
She is effectively saying that the unvaccinated are a danger to the vaccinated, and this needs to be balanced by making life easier, and safer, for the vaccinated.
This is not inaccurate. The unvaccinated are more likely to catch a symptomatic infection, pass it on, and get so sick that they take up hospital resources that would otherwise be available to all, including the vaccinated.
But it's also a clear shift away from Government language about the virus, not people, being the threat.
Otago University Associate Professor and medical ethics lecturer Angela Ballantyne said the key question was whether the limits on the unvaccinated are justified.
It's a big deal to limit the freedoms of people who don't do something that's voluntary, she told Q+A, and it was up to the Government to explain why it's necessary in a way that ensures a high degree of public buy-in.
It's also relevant to consider whether the goal could be achieved with fewer restrictions.
Ardern considered allowing more freedoms for unvaccinated people with a negative test, but pointed to the experience in Germany.
There, the unvaccinated could get a free test and, if negative, were allowed the same access to bars and restaurants as the fully vaccinated.
They were then made to pay for the test. The justification was that the vaccinated shouldn't have to foot the testing bill for the unvaccinated wanting to head to the pub.
To incentivise getting vaccinated, businesses were then allowed to refuse entry to the unvaccinated, regardless of a negative test.
Ardern said a negative test was less "bulletproof" than being vaccinated, but it was also about the use of resources.
"We don't want people who don't need to be tested in that way routinely using up our [testing] resources."
Her goal is to minimise the spread of Covid and protect people in a way that isn't overreach.
The traffic light system minimises the risk of super-spreader events among unvaccinated people. Without vaccine certificates, gatherings are restricted to 100 people under Green, 50 under Orange, and 10 under Red.
This will also apply to faith-based institutions, an acknowledgement of the role of super-spreading church events in previous outbreaks, as well as the current one.
Hospitality businesses that don't use vaccine certificates will only be able to operate in a contactless way under Orange and Red, and can only have up to 100 people under Green.
Consider too that a group of public health experts have questioned whether Auckland will see Green in the foreseeable future, given how much Delta has spread there.
That effectively means such businesses won't be viable unless all their workers and customers are fully vaccinated, so if you work in that industry and don't want to get jabbed, you'll probably need to find another career.
The same goes for close contact businesses like gyms and hairdressers, which won't be able to operate under Orange or Red unless they use vaccine certificates.
All up, the Government estimates that 40 per cent of the workforce will need to be fully vaccinated.
Both National and Act say this is all too much, and too divisive. They both support vaccine certificates, but they want businesses, rather than the Government, to decide on their own restrictions to minimise the risk of spread.
It's unclear how long different sets of rules will apply for different people, though the legislation enabling the certificates will be periodically reviewed.
Modelling has shown that vaccination on its own is not enough for herd immunity in a Delta environment unless there is 97 per cent population coverage.
In other words, if you don't want the health system to be swamped, there'll need to be some public health measures and social restrictions.
In Denmark, for example, all domestic restrictions were dropped when 80 per cent of the eligible population were fully vaccinated, but daily cases are now pushing 1500, while a handful of people die every day.
Denmark has a similar population size to New Zealand, as does Singapore, which has reintroduced Covid restrictions as cases surge beyond 3000 a day, daily deaths tip into double figures, and ICU capacity is pushed to its limit.
This is likely too high a price for Ardern, so social restrictions will remain part of the toolkit.
That could change if, for example, a vaccine evolved to be 100 per cent effective against any and all variants of the virus, and which could be administered to everyone.
In the absence of that, a two-class system seems likely to be part of the new normal for the foreseeable future.