[mikedilger]

While not disagreeing with that, I think we can continue to eliminate. During level-4, the R value is clearly lower than 1.0 meaning the infection shrinks. And the infection is small since we locked down immediately when a community case was first found. Six weeks will probably do it... so long as we don't have (a) new cases coming in through the border, or (b) infected people flaunting the lockdown rules and spreading it faster than we can contain it. Indeed, if it blows out past a couple thousand or so, we will need to pivot.

[koyote]

> During level-4, the R value is clearly lower than 1.0 meaning the infection shrinks

Delta is a different beast.

Here in Australia, Victoria managed to get the Reff rate down to ~0.75 during their OG outbreak last year with a strict lockdown. Delta has an R0 that is multiples higher than the OG strain so the same lockdown would not get it below 1. You can look at Victoria's current outbreak for evidence of this.

Now that doesn't mean NZ can't beat it. A part from Auckland, the population density is very low and as long as compliance is high you might be able to just about get it back down again; especially if you manage to keep it out of large households and essential workers.

I just wouldn't base my expectations on what worked last year as Delta is quite a different game.

[AussieWog93]

>You can look at Victoria's current outbreak for evidence of this.

Also worth noting that peoples' behaviour is very different this time round compared to a year ago. A lot more people are flouting the rules or at least coming up with creative ways to see their friends while technically not breaking the law. After 200+ days, everybody's just sick of it.

[beachy]

I agree, elimination still looks a good strategy, it's too early to give it up yet. If we can punch out the current outbreak (I'd put money on it, but not too much) and get back to zero then that will re-legitimise lockdown as a strategy for a bit longer.

We've got a few "open 'er up and let it rip" friends and I just don't get it. There are so many potential game changers when you are an island. If a reliable saliva-based test appeared that produced results in say 2 hours we could reduce MIQ and use waiting booths at the airport. Even if it was only 99% accurate we could pool groups of 20 into rooms together while waiting for results. So many possibilities if we continue to think critically instead of politically.

[ImaCake]

A quick word on test attributes and why we still don't have a more rapid test than PCR.

Tests for disease rely on two numbers:

1. "sensitivity" - the proportion of people with COVID who get a positive test

2. "specificity" - the proportion of people without COVID who get a negative test.

COVID, despite the media attention, is a rare disease compared to the number of people tested. Say we have 10,000 people tested for COVID at the airport. We have 99% sensitivity and 99% specificity. And we know 100 people have COVID (1% prevalence) in this group. Our test would find 99/100 of the positive cases. But it would also find an additional 99 false positives! It also misses one true positive case. Which would be disasterous for the quarantine measures in place in Australia and NZ. In short, even a gold standard rapid test is not enough, although at 99% specificity and sensitivity it would be somewhat useful.

This is a lot less intuitive than it looks. The companies pushing rapid antigen tests at the start of the pandemic would have know better, but they chose to lie to the public about this.

https://en.wikipedia.org/wiki/Sensitivity_and_specificity