The use of saliva tests and rapid antigen self-tests is to be dramatically expanded in hospitals, schools and other workplaces, as the Government gives itself emergency powers to take over private medical laboratories.
Trials of high-speed, low sensitivity antigen tests at Auckland Airport and Middlemore Hospital have successfully detected new Covid cases – so now the Government is preparing to authorise their wider use in the new Covid suppression strategy.
The airport – alongside Mainfreight, Z Energy, Foodstuffs, Woolworths and other big companies – is asking to be allowed to import the tests. A group of more than 25 businesses have formed a coalition to jointly import 370,000 rapid antigen tests to be introduced on work sites around the country.
The tests are used commonly for home screening in the UK and some other countries, where Covid is prevalent, and the Government is understood to see them as a useful complementary tool to the more sensitive “gold standard” nasal swabs and saliva PCR tests.
Antigen and antibody tests are banned in New Zealand, because of fears they might undermine the more sensitive PCR testing, but the Ministry of Health issued itself an exemption to purchase 100,000 test kits for the pilot. Now, that trial is set to be widened in preparation for their nationwide use.
On Thursday, Prime Minister Jacinda Ardern will announce plans to roll out testing much more widely, after a report from Professor David Murdoch, of Otago University. Murdoch leads the Government’s testing advisory group, and Ardern says his work will form the basis of “a new rigorous testing regime that will be central to our strategy to control the virus” over coming months.
Next week, the Government is to announce plans for staff and children to return to school on October 18. Education Minister Chris Hipkins faces pressure from parents to mandate vaccination for teachers and school support staff – a solution that has been implemented in Victoria and New South Wales, and remains on the table here.
“There is other legislation where the Government can come in and expropriate or requisition private property – that’s the Public Works Act. But that has more protections, like a process to determine a market rate that the Government must pay…. They can just insist we give up our stock and our reagents and our premises that we need to do our work.”
– Leon Grice, Rako Science
But equally importantly, Hipkins is set to confirm the regular testing of teachers and support staff to protect unvaccinated under-12s on their return to the classroom.
Given the vulnerability of young school pupils, the front-running candidate for teacher testing is a saliva PCR test, which can detect the low viral loads when people are first infected, and infectious.
The antigen tests are less sensitive; tests indicate they pick up less than half of early Covid cases, though they are up to 93 percent reliable about a week in, when the virus is at its most transmissive.
That is why the Ministry of Health and private testing companies like Rako Science see them as supplementing PCR swabs. For instance, said Rako director Leon Grice, they might be used in less critical workplaces where an occasional shutdown would not incapacitate the business, or they might be used to alternate with saliva PCR tests in a twice-weekly testing regime.
The Government has introduced a new law allowing the Ministry to take over private medical laboratories and requisition their testing supplies. That has upset Grice, who said Rako Science was not consulted on the hardline law change. The company, which already provides saliva tests for a list of private hospitals and other companies, had offered to contract its testing services to the ministry.
That offer was declined, but the new law would instead allow the ministry to just take over Rako’s laboratories, Grice said, and pay only a price that it unilaterally decided.
“The advantage of rapid antigen testing is that it gives a result quickly allowing a positive individual to be isolated, while a PCR test is undertaken. However … antigen tests tend to be less sensitive at detecting cases, especially in asymptomatic persons.”
– Darryl Carpenter, Ministry of Health
“There is other legislation where the Government can come in and expropriate or requisition private property – that’s the Public Works Act,” he said. “But that has more protections, like a process to determine a market rate that the Government must pay. Why haven’t they put those protections in this law? Instead, they can just insist we give up our stock and our reagents and our premises that we need to do our work.”
The bill does provide for “market rate” compensation, but that rate is determined by the ministry. A ministry spokesperson said the law change was intended to bolster the existing legal powers under the Health Act 1956. “There are no current plans to create any orders under these provisions, but they will be a necessary emergency power if there is an unmitigated outbreak in New Zealand where the Covid-19 testing supply and facilities must be regulated,” he said.
“The range of measures in the Bill have been introduced to better support the Government’s response to Covid-19 as we better understand the longer-term impacts and the required response measures evolve.”
“Covid-19 is likely to be a prevalent public health concern for months, if not years, to come. The public health measures contained in the Act, therefore, will remain relevant for the immediate future as we safely but progressively open New Zealand’s borders.”
– regulatory impact assessment
The Bill of Rights protects New Zealanders against “unreasonable search or seizure … of the person, property, or correspondence”. Attorney-General David Parker hasn’t raised any concern about the seizure of laboratory premises and consumables, in his advice on the new Covid-19 Public Health Response Amendment Bill.
However, a regulatory impact assessment does acknowledge costs to both government and business, and to individual rights. It says that is justified, in order to regulating quality control and minimum standards in Covid testing, to integrate test results into the national public health testing repository, and to manage the supply of testing consumables in the event of shortages.
“While the rollout of vaccination programmes has raised hope that the peak of the pandemic may be over, Covid-19 is likely to be a prevalent public health concern for months, if not years, to come. The public health measures contained in the Act, therefore, will remain relevant for the immediate future as we safely but progressively open New Zealand’s borders,” the assessment says.
“It is possible to enter into agreement or Memoranda of Understanding with laboratories; however, this would take considerable length of time and the outcome is not guaranteed, particularly with private market laboratories. It is also likely financial compensation would be expected.”
The National Party has been pushing for the rollout of saliva tests and rapid antigen tests. Spokesperson Chris Bishop said Rako Science had set the standard for highly-sensitive saliva tests in New Zealand, and he would seek to amend the new law at the select committee to provide greater protection for such private providers.
“As Covid now risks being established in Auckland, stronger systems are needed to keep Covid heavily suppressed while the vaccination roll-out completes.”
– Dr Eric Crampton, NZ Initiative
A report published this morning by the NZ Initiative, a business-funded think-tank, also recommends New Zealand set in place stronger testing systems, including preparing for regular saliva-based PCR testing in schools, and readying rapid antigen testing for deployment where suitable.
“As Covid now risks being established in Auckland, stronger systems are needed to keep Covid heavily suppressed while the vaccination roll-out completes,” said the report’s author, Dr Eric Crampton.
The Ministry of Health’s Science and Clinical Technical Advisory Group supports the use of rapid antigen tests as part of a pilot where it is used as a surveillance tool to support our public health response.
Darryl Carpenter, the ministry’s group manager for Covid-19 immunisation, testing and supply, said the two pilots of rapid antigen testing would show how they could identify new infections, support outbreak investigations through screening and monitor disease trends.
It is being used for visitors and patients arriving at Middlemore Hospital’s emergency department, and for point of arrival testing for selected travellers at international airports.
“The advantage of rapid antigen testing is that it gives a result quickly allowing a positive individual to be isolated, while a PCR test is undertaken,” he said.
“However rapid antigen testing requires a much higher quantity of the virus to be present in the sample. As a result, antigen tests tend to be less sensitive at detecting cases, especially in asymptomatic persons or people who are either very early in, or towards the end of, their infectious period.”
Carpenter said most rapid antigen tests used a front of nose swab to detect the presence of viral antigen that indicated active current infection, rather than the deeper nasopharyngeal swab used for PCR tests. “The sensitivity of the test is reduced when used for self-testing by asymptomatic individuals who may take a poor sample or conduct the test incorrectly,” he warned.
“Because we have had relatively low Covid-19 prevalence in New Zealand, the sensitivity of testing methods is important. By using testing with high sensitivity, we reduce the risk of missing a positive case.”
– Darryl Carpenter, Ministry of Health
Saliva PCR tests are more reliable than antigen testing, but take longer because the testing of the sample is undertaken by an accredited laboratory. If someone returns a positive saliva test, the ministry then requires an additional “gold standard” nasal swab.
Saliva tests are already used for the border workforce and permitted workers crossing alert level boundaries. “Because we have had relatively low Covid-19 prevalence in New Zealand, the sensitivity of testing methods is important,” Carpenter said. “By using testing with high sensitivity, we reduce the risk of missing a positive case.”
But that is changing, with the Prime Minister’s indication on Monday that New Zealand is moving from an elimination strategy to a suppression strategy, which would accept small numbers of Covid cases in the community and ICUs.
The Ministry of Health’s science and clinical teams are currently considering rapid antigen and saliva tests, and how they could be used in the New Zealand context of low prevalence of Covid-19 – which is the current case and likely to continue.
Carpenter said the ministry was continuing to keep abreast of developments in science and in public health thinking, with changes in the virus, as part of ensuring its approach to testing for Covid-19 was effective, and adapted when needed. “That’s why we do not always immediately adopt testing processes that are implemented in other countries where Covid-19 is more prevalent,” he added.
Mainfreight’s managing director Don Braid said his company, with the airport and others, were seeking urgent approval from the Government to allow for the importation of rapid surveillance tests as a critical part of health and safety management in the workplace.
“This is business wanting to take care of their people from a health and safety perspective and to keep their sites operational,” he said. “Vaccinations and testing are key to this and it is bewildering that the rapid testing we are using in 26 locations around the world is unavailable to us at our home base in New Zealand.
“We believe the Government shares our concern that the addition of antigen testing cannot suffer the long delays that occurred in introducing saliva testing. With the current Delta outbreak we are confident they will act decisively and work with us to make it happen.”
The coalition of 25 companies plans to import its 370,000 tests through medical supplies wholesaler and distributor EBOS Healthcare, and have written to the Government seeking emergency clearance to import the tests within the next seven days.
The tests, which provide results in about 15 minutes, would not take the place of existing PCR tests for border workers or those who are experiencing symptoms. Five of the six rapid tests under consideration are already approved and in use in Australia with a final option currently under an approvals process.
Foodstuffs North Island Chief Executive Officer Chris Quin said the company was focused on keeping its team and customers safe and rapid antigen testing would provide a quick and easy way for key staff to test themselves frequently at home or at work.
“Covid-19 isn’t disappearing any time soon,” he said. “We want access to fast testing to provide an additional layer of screening for our essential workforce, who have been hugely co-operative in doing the right thing for each other and New Zealand from a health and safety perspective.
“The tests are proven to be very effective when used frequently. They can only strengthen and improve our current plan for managing the virus as an additional layer of protection as we move towards living with COVID-19. It’s a lot like a high-vis jacket – they don’t protect from every accident but they’re another important tool in helping to keep people safe.”
Genesis chief executive Marc England said rapid antigen tests would add another layer of protection for staff at critical power plants such as Huntly.
“We initiated saliva testing among our essential workers at Huntly during alert level 4 and this provided assurance our staff and the plant could operate safely,” he said. “The half-day turnaround for saliva results is good, but the immediacy of rapid antigen testing means our staff will have reasonable confidence before they step foot on site that they are safe to do so.”
The 25 companies requesting urgent approval to introduce the tests at critical worksites include Hynds Pipe Systems, Mercury, Summerset Group, Wellington Airport, Christchurch Airport, Sky NZ, Queenstown Airport, Spark, Vodafone, The Warehouse Group, ANZ Bank, Contact Energy, Fulton Hogan, Fletcher Building, Chorus, Carter Holt Harvey, Meridian Energy, DHL Express NZ and Air New Zealand.
Minister Chris Hipkins said the companies’ motivation and initiative was good, in seeking additional tools for Covid surveillance, though it was unlikely they would get their approval within the seven days they requested.