Scrapping MIQ for overseas arrivals when Omicron takes hold would "will free up a lot of resource which will be badly needed elsewhere," according to a report by Auckland DHBs.
The document by Counties Manukau, Auckland and Waitematā DHBs outlines how the Omicron surge could play out, and what might be done to try and cope - including shorter stand-down periods for Covid-positive workers who don't have symptoms.
The health workforce will come under immense pressure. Auckland Hospital staff, for example, have been told a quarter of workers could be unable to work at the height of the outbreak, mostly due to having the virus themselves but also family and childcare.
A report written by Dr Gary Jackson, director of population health at Counties Manukau DHB, earlier this month modelled scenarios including almost 2000 cases a day in the Auckland region in just six weeks.
That modelling was publicly released last week, but the full "Metro Auckland Covid modelling for 2022" report was withheld. It has now been obtained by the Herald, and contains revealing commentary that, the authors' stress, is "initial thinking for discussion", and not official policy.
One suggestion: end MIQ for overseas arrivals when the virus is widespread.
"MIQ facilities will still be important to assist those who are unable to isolate safely at home, but their role for border travel control will likely be over. Once Omicron is circulating freely there will be little/no added risk to New Zealanders from overseas travellers. This will free up a lot of resource which will be badly needed elsewhere," the report states.
Covid-19 Response Minister Chris Hipkins has said there is "no question" the country would still move to a self-isolation model for international arrivals, but exact timing is unclear.
A spokesperson for the minister told the Herald that the end of February remains the default start time as previously agreed by Cabinet, "pending further considerations".
"How this will work in practice, including dates, is being considered by Cabinet and an announcement is expected in the next couple of weeks. These discussions and considerations will include how MIQ will be best used over the mid to long term."
Prime Minister Jacinda Ardern was pressed on when the move to self-isolation would happen in Monday's post-Cabinet press conference, and said the Government's goal was to slow down the spread of Omicron.
"So that, yes, we will see an increase in cases, but we want our health system to be supported to manage those. That means being mindful about our reopening."
Meanwhile, hospitals are braced for a surge in cases. Omicron generally causes less severe disease, the Metro Auckland Omicron report notes, but the huge numbers of patients will put significant pressure on hospitals, emergency departments and primary care.
"Given such prevalence, staffing impacts (rather than illness severity per se) are likely to be the major problem, as infected staff are required to stand down – affecting all essential industries, not just health. New regimes for asymptomatic positive staff may be required – vaccinated-boosted folk will shed virus for a shorter length of time."
(The Herald understands the greater Auckland DHBs are currently reviewing stand-down periods for Covid-positive staff.)
'Differing living circumstances can greatly change the risk profile'
Included as an appendix is a related report, which analysed the vaccination status of Aucklanders who caught Covid-19 in November last year.
In total, 71 per cent of infections in those aged 12 and over were in those not fully vaccinated, despite that group being only 15 per cent of the 12+ population.
Of people unvaccinated and aged 12+, 4.1 per cent of Māori, 1.6 per cent of Pacific and 0.6 per cent of European and Asian people got Covid-19 in November - a 12-fold difference between Māori and European, and a five-fold difference between Pacific and European.
"This has three main facets – the specific trajectory of the current outbreak, the clustering of unvaccinated people facilitating the spread, and the differing whānau mixing patterns of the respective populations increasing the interactions and therefore opportunities for virus spread," Jackson concluded.
"While the vaccination is offering the same protection for Māori and Pacific people, differing living circumstances can greatly change the risk profile."
The standard time someone is infectious with Covid-19 is about 14 days, the report noted, but this is roughly halved to around seven days for the fully vaccinated.
"This means that if your social circles and social interactions include unvaccinated people, they are twice as likely to be infectious to you … the November phase of this outbreak saw significant spread in Māori communities (51 per cent of cases), so even Māori who were fully vaccinated had an increased chance of interacting with a case."
'Vaccination rates seem the most important factor'
The Omicron modelling report, dated January 12, notes that there is a lot of variation when looking at case, hospital and death rates from other countries.
"While high vaccination rates seem the most important factor, other factors include the governmental approach and population acceptance of risk mitigation measures such as indoor masking.
"Take for example Spain and Portugal. Both have a high vaccination rate, (Portugal is also 34 per cent boosted), but Portugal is said to have the better compliance with risk-lowering behaviours. Both countries have an large Omicron increase in cases, but Spain's is higher and is reflected in hospital cases, while Portugal's is half as much. A multilayer protection strategy, including science-based governmental decisions and media coverage is important.
"Standard infection protocols developed for previous covid variants remain entirely relevant for omicron – mask use indoors, PPE, handwashing, scanning etc."
What is also clear, the report states, is the importance of vaccination: "People with a recent second dose, or who are boosted, remain largely protected from serious consequences."
The Omicron modelling used a hypothetical start date of February 1, and projected cases across Counties Manukau, Waitematā and Auckland to peak at about 1500 to 1800 a day by mid-March through April, before dropping away to 150 to 330 a day through May to September.
Over this period they modelled about 175 to 190 hospitalisations a month due to Omicron in March and April, falling to 45 to 70 throughout May to September.
Those requiring intensive care numbered between 10 to 20 across March and April, falling to five to 10 across May to September. Their models did not look at death rates.
The models showed a rapid increase in Omicron cases from the start of any outbreak over six weeks, levelling off over about four weeks and then dropping over another six week period.
On the veracity of the numbers Jackson said cases could "easily be double or triple", but they were optimistic given how New Zealand had responded to outbreaks in the past and high vaccination rates.