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(Image: Tina Tiller)

Covid-19July 6, 2022

How do Aotearoa’s Covid regulations compare to the most up-to-date science?

a yellow image showing a map of New Zealand + a virus + a vaccine = ...
(Image: Tina Tiller)

After nearly three months at the orange light setting, Shanti Mathias asks the experts if our current regulations still fit.

Aotearoa has been at the orange light setting, with widespread community transmission of Covid, since mid-April. In that time, more than half a million people have caught Covid. With Covid hospitalisations the highest they’ve been for months, and the BA.5 variant spreading, The Spinoff talked to microbiologist Siouxsie Wiles and epidemiologist Michael Baker about how the ever-evolving science does and doesn’t align with Aotearoa’s current Covid regulations.

Does two doses mean fully vaccinated?

While vaccine mandates have largely been phased out, except for healthcare workers, there’s widespread uncertainty about how many doses of the vaccine offer full protection. Second boosters for immunocompromised people and those over 50 have been available since June 28. Across the government websites which provide information about Covid, the first two doses of a mRNA Covid vaccine are now referred to as a “primary course” of the vaccine, rather than “fully vaccinated”, although this isn’t entirely consistent

Scientists say that the term ‘fully vaccinated’ needs to be replaced with ‘up to date’. (Image: Getty)

“Your vaccination should be ‘up-to-date with current criteria’,” suggests Baker, as an alternative description of vaccine status. A booster is essential for protection against omicron. Vaccine doses in the future may be tailored to providing maximum protection against particular variants of the virus. 

While 95% of eligible New Zealanders have had two vaccine doses, only 68% of that group have had a third booster dose. False perceptions “that the boosters are optional extras combined with the idea that omicron is mild, which is simply not true” may contribute to a lack of booster uptake, Wiles says. 

Test for reinfection after 29 days

On June 30, the guidance around Covid reinfection was updated, changing from not having any requirement to retest for Covid within 90 days of an infection to 29 days. “The latest evidence shows that getting reinfected with Covid-19 can occur within a short period of time,” says the government’s Covid website. However, household contacts of a case who have had Covid in the previous 90 days still do not need to isolate.

The 90-day regulation may have prevented health agencies from getting accurate data about reinfection – there is very little available data on reinfection in New Zealand – although it made sense when the primary testing method was PCR tests, which are more sensitive to any viral load. The Spinoff spoke to Baker and Wiles before the 90-day reinfection guidance changed.

Rapid antigen tests are an easy way to work out if you have been reinfected with Covid (Image: Ezra Whittaker)

“We don’t know much about reinfection in New Zealand because the advice has been for people to not get tested if they were within three months of having Covid,” says Wiles. “It’s clear now that people can get omicron more than once. If people’s symptoms reappear then it’s important for us to understand if someone has been reinfected or if they might be chronically infected. Because rapid antigen tests basically detect infectious virus, it’s crucial people get tested to help answer that question.”

Baker agrees. A cut-off date for reinfections is arbitrary, but 90 days was too long. “Reinfection is unusual within the month,” he says. “But there are well documented cases of people getting Covid within three weeks. We shouldn’t have any barriers to having something declared as a reinfection because it can happen.” 

Is seven days long enough for isolation? 

Current regulations say that “you can end self isolation seven days after your symptoms started or you tested positive, whichever came first. … You do not need a negative RAT to end self-isolation”. Guidelines also recommend that those with ongoing symptoms stay in isolation until 24 hours after their symptoms resolve. 

The science around infectiousness is complex, and very case-dependent. As many as one in four people can still be infectious seven days after symptom onset, says Wiles. Given this, RATs are a useful tool: “the beauty of using rapid antigen tests is that we have a quick and easy way of telling if someone is likely infectious. We should be using those and making sure people are staying isolated if they are still testing positive,” she says. If someone continues to test positive for several weeks, then they may be chronically infected. 

Wearing a mask after the seven-day isolation period has ended will help to prevent spread of Covid to others (Image: Tina Tiller)

“Seven days is a compromise,” says Baker. In other countries, such as the US, isolation ends after five days, but Covid cases are encouraged to wear a mask while in public to avoid infecting others. While a mix of consistent mask wearing and a “test to release” could prevent still-infectious people from spreading Covid after their isolation ends, Baker says that adding these layers into the Covid regulations would increase the complexity of guidelines and make it more difficult for people to adhere to. 

Why the regulations and science don’t match

“The regulations are a tradeoff between protecting people and the government getting society moving again,” says Baker. He compares Covid regulations to the road toll: while the interventions to prevent people getting killed on roads are well known – slower speeds, road barriers, and so on – the appetite to go places fast means that there is limited social licence to apply these limits to how people move on roads. 

Similarly, the ways to reduce the harms of the pandemic are well established. Increasing vaccination coverage, reducing virus transmission and caring for positive cases are what Baker calls the “three big opportunities” to minimise the impact of Covid. 

Given that Covid hospitalisations are currently the highest they have been since April, it could be time to revisit how Covid guidance limits harm. Baker suggests that employers could be supported to encourage a seven-day isolation period for workers with any respiratory infection, not just Covid. “We’re still in a pandemic stage,” he says. “Covid isn’t endemic yet.” If the current mortality rate of around 10 deaths a day continues all year, it will add 10% to New Zealand’s annual mortality. 

“We’ve got to balance protection against Covid with [limiting] the economic and social consequences [of restrictions],” Baker says. Currently, the mechanics of these trade offs aren’t explicit enough – and those who are most affected are not the people making decisions. Baker says it’s “the old, the vulnerable, and the disabled” who have had to reduce their social interaction due to the danger of Covid. “Their world has shrunk.”  

Keep going!
The depths of winter could mean a return to the Covid peaks of March. Image: Tina Tiller
The depths of winter could mean a return to the Covid peaks of March. Image: Tina Tiller

SocietyJuly 5, 2022

Covid’s winter wave is here. What’s driving the surge, and how can we fight it?

The depths of winter could mean a return to the Covid peaks of March. Image: Tina Tiller
The depths of winter could mean a return to the Covid peaks of March. Image: Tina Tiller

A new variant has added fuel to the winter fire, bringing a marked rise in cases and hospitalisations. And it will get worse before it gets better.

Whether or not we want to hear it, “post-Covid” is a misnomer. It is true that New Zealand avoided the worst ravages of the pandemic, by closing the borders before vaccines became available and amid the most severe variants. And yet today, across the most telling metrics for Aotearoa, numbers are not in fact declining. Nor are they plateauing. They’re discernibly angling up. “We’ve had one full week of consistent increases in cases,” said Covid modelling expert Michael Plank. “Broadly speaking it is very likely that we are at the start of a wave – and this is what we’ve been expecting for some time.”

There’s one sample group of 24 that sheets home the prevalence. Admittedly, we’re not dealing with a cross-section of society, and Labour ministers travel a good bit more than most of us, but still: of those 24 ministers, 20 have contracted Covid-19, including four who are currently isolating with the disease. So far, none has had the misfortune to catch it for a second round, despite the increasing reports of reinfections across the country.

The numbers now – and how high they could get

So much for ministerial infections. What picture do the broader measures paint?

The reported cases number substantially undercounts the true figure, given it relies on people testing and reporting positive results. But the direction is grimly clear. Yesterday saw 6,498 new cases, with the seven-day rolling average on the rise for the past 10 days. It currently sits at 6,878, the highest for more than a month. 

As was clear from the start, hospitals are at the epicentre of the pandemic. In omicron, the impact is felt more sharply in ED than ICU, but that makes it no less capable of straining, sometimes to breaking point, resources that are already under massive pressure in the depths of winter. Last month, New Zealand emergency doctors said their departments were “under extreme and unprecedented pressure”.

Yesterday’s hospitalisation numbers are striking. The ministry reported 487 people in hospital with Covid-19. The last time that number was so high was 10 weeks ago, on April 26. Since falling to 300 on June 23, the number hospitalised has climbed across 11 days by more than 60%.

One of the reasons this has outstripped the growth in case numbers, Plank suggested, was the extent to which the disease has infected older people compared with the March peak. Case numbers among over-70s were “now at an all time high”, he said. 

Covid’s death toll continues to mount. The total number of people who have died with Covid-19 in New Zealand increased by eight to 1,527 in yesterday’s update. The last seven days have brought an average of 14 deaths per day. 

Recent days have brought warnings that case numbers could soar back towards the heights of March, when the average of new recorded daily infections topped 20,000. A number of unknowns are in play, but, said Plank, a professor at the University of Canterbury and chief investigator at Te Pūnaha Matatini. “It’s certainly possible we’ll see those sorts of numbers.”

A collision of factors

The resurgence in Covid in Aotearoa can be attributed to at least three trends. 

First, the new subvariant.

Omicron BA.5 has established a foothold in New Zealand and it is moving fast. The data showed BA.5 “rapidly increasing” and expected to outstrip BA.2 as the dominant variant in the weeks to come, said Plank. The experience in places like South Africa, the UK and Portugal is instructive on its “growth advantage”, he said. “It’s much better at getting around our immunity.”

BA.5 has “managed to shapeshift a little bit of its spike protein”, so proving more “sneaky” against existing vaccines, according to immunologist Graham Le Gros.  

Second, it’s winter

As evidenced across the course of the pandemic – and in colds and flus forever  –  the coldest season propels the contagion. The explanation is straightforward. “One of the biggest impacts of being in winter is people tend to be inside more,” said Plank. The airborne coronavirus thrives in the “high risk environments” of enclosed, crowded spaces where ventilation is lacking.

That flu factor exacerbates the pressure on the health system. In 2022, after a couple of years with flu largely locked out at the border, a bonus of the Covid elimination approach, the floodgates have opened. Even without Covid, then, “hospitals are already incredibly busy because of the flu and other winter ailments”, said Plank.

Third, immunity is waning

As a population, we’re becoming less immune by the day. Our collective resistance – “a combination of vaccine immunity and infection-derived immunity” – is dimming, and that opens fresh chinks in the armour, especially against the more ravenous BA.5.

Last week the Covid response minister, Ayesha Verrall, announced that the reinfection risk – compounded by the spread of BA.5 – meant a change to the rule that had previously exempted anyone who had tested positive for Covid-19 from re-testing for 90 days. That has now been slashed by two thirds. As of today, if you experience symptoms and it is 29 days or more since your initial infection, you must test; if positive, isolate for seven days. 

What can we do about it?

“Number one,” said Plank, “is still the vaccine. If you’re eligible for the vaccine now is the time to go and get it. This is still by far the best tool we have.” 

While Ministry of Health statistics put the total number of people who have had two primary doses at a formidable 95%, that number drops to 73% for the third, or booster, shot. It is lower still for Māori (56%) and Pacific people (60%). Many people are now also eligible for a fourth dose. Covid vaccines remain free for all. More details are here.

Flu vaccines make a difference, too. They’re currently available via GPs and some pharmacies and free for anyone aged 3-12 or over 65, as well as for Māori and Pacific people over 55.

Plank also urged people to use masks indoors, to test if any symptoms crop up, and not to slacken on staying at home if you have an flu-like symptoms. As for government settings, there was a case to “expand the mask requirements”, he said. 

Last week Verrall announced that the country would remain in the orange Covid setting. “Moving back to red is unnecessary at the moment,” said the minister in a statement. “We can continue to manage the virus at orange, but are putting in place a range of additional measures to help manage a recent rise in cases.” Those measures included the shift in reinfection guidance to 29 days and mask and ventilation provisions for schools.


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