Good morning Auckland. It's 'Freedom Day'... so now what for our Covid-19 story?

How vaccination helps prevent the spread of Covid-19 (with te reo Māori subtitles).

ANALYSIS: After more than 100 taxing days of lockdown Auckland now emerges, blinking, into a new reality.

For some, today will be deeply concerning, our final and definitive surrender to a coexistence with a virus that is particularly dangerous to the old and vulnerable.

For others, it will be a day of celebration. Now the fully vaccinated can get a drink at the local bar, sip coffee in the local café, eat inside a restaurant. People can finally go to the homes of family and friends. Aucklanders have certainly earned this slice of normalcy.

Yet today is not normal. At best, it’s normal-adjacent. The virus is here and for all of us a simple question looms large: now what, New Zealand?

* Covid-19 NZ: Just how deadly is the virus?
* Covid-19 NZ: Why the vaccines' imperfections matter
* Covid-19 NZ: What Auckland opening means for the rest of the country

Predicting the trajectory of the Covid-19 pandemic is treacherous. A week before Delta arrived at our shores Prime Minister Jacinda Ardern insisted elimination was still viable in the medium-term. Two weeks ago, we’d never heard of the Omicron variant.

What we do know is that our ongoing battle with the virus can be partially defined by the Reproductive, or R number. This tells us, on average, how many others a person with the virus will infect. When it’s above 1 an outbreak is growing. Below 1, and over time, case numbers will fall.

In mid-August, the R number was about six as Delta spread invisibly at first, before that 58-year-old Devonport man tested positive and everything changed.

Since then, Delta has sought to only make more of itself, yet it’s been stifled by the lockdown and an ever rising vaccination rate. Finally, these measures appear to have pushed the R number below 1.

If Auckland stayed in lockdown (and people obeyed the rules, of course) it would likely stay there.

New Zealand changed its rules for managing Covid-19 on December 3, switching to a so-called 'traffic lights' system.
Kathryn George/Stuff
New Zealand changed its rules for managing Covid-19 on December 3, switching to a so-called 'traffic lights' system.

But Tāmaki Makaurau can’t stay shut forever.

What today’s move to the traffic light system does to the R number is uncertain. It should, in theory, push it upwards. But that certainly won’t show in Saturday’s case numbers. It won’t show in Monday’s. It’ll be a week or two before we see any impact, if there is one.

The only thing I can say with any certainty is that the struggle for the R number is on. On one side, there are the restrictions mandated by the traffic light system, mask wearing, contact tracing, testing, the fact it’s summer and people are outdoors may help.

On the other is normalcy – going to bars, seeing family and friends; all perfectly human things that unfortunately help distribute the coronavirus.

We have another ally. Auckland’s (and New Zealand’s) vaccination rates are world-class. Yes there are clear gaps, particularly in younger Māori but the coverage in all elderly people is excellent.

The rapid acceleration of the vaccine roll-out also means the population as a whole is now very, very immune, particularly those younger, more mobile Kiwis who’ve had the jab in recent months. This should continue to impart downward force on the R, until significant waning kicks in, at least. By then, the administration of third doses should be well underway.

You can probably now get a sense of how the push and pull on this mathematical expression, R, will ultimately define how the traffic light system is applied. While the Government insists raw case numbers are now less important, they are not unimportant.

Even though the proportion of cases needing ICU care has dropped off significantly in the last month, a surge in Covid-19 case numbers can still put pressure on hospitals. If Auckland was moving to the old alert level 1 on Friday, Professor Michael Plank told me he’d expect the R number would rise to about 1.5.

Within the traffic light framework, the R number will likely be between 1 and 1.5 – hopefully towards the lower end of the scale, Plank said, pointing to NSW, which has reopened and kept case numbers suppressed.

If the R number hovers around 1, things should be OK but what if it creeps upward towards 1.5? Then what? How will a government that has taken an incredibly cautious approach to Covid react?

(And keep in mind Auckland’s borders don’t open for a few more weeks.)

This leads us to the other push and pull of the coming months – the politics of Covid.

In a piece for The Times last year, Professor Graham Medley of the UK’s Sage pandemic modelling group explained it like this: “Both the virus and the ways of tackling it cause harm and need to be balanced: for example, how much should young people’s education be compromised to protect older people from infection? This is a ‘wicked problem’ with no winners in which we are trying to trade jobs, freedoms and health against each other without knowing the rate of exchange.”

New Zealand had managed, until August, to basically sidestep the awful trade-offs of this pandemic. Those days are over. The politics of no Covid was simple. The politics of some Covid will be messy.

In the background, the new Omicron variant awaits like a long teased-at villain in an upcoming blockbuster sequel.

Soon, we’ll better understand the variant. But what if it’s worse than Delta? Then the dynamics of this pandemic will be further warped. Then the question will very much be: what now?