With an announcement regarding a potential loosening of strict physical distancing and travel rules due today, how prepared are we to lower our defences against Covid-19?
Digging into the details
How far down the track is New Zealand and the world from normal, or at least a new normal, where small outbreaks of infections are able to be controlled? Are our local systems robust enough to catch and stop a second, third or fourth wave of the virus while the worldwide search for a vaccine and treatment continues?
The Level 4 lockdown, and strict rules of Level 3 have seen New Zealand smash the curve of the virus flat. The rules in Level 2 are not as stringent.
When a shift down to Level 2 happens, domestic travel will be allowed, staff and customers will return to workplaces and schools will reopen. Gatherings of more than 100 are still a no-no but bars and eateries will once again be allowed to host patrons, as long as some safety rules are followed.
The border will still be mostly closed. New Zealanders abroad will be able to return home but must spend two weeks in quarantine.
Can we test enough to catch outbreaks?
When the first cases of Covid-19 emerged in New Zealand, the ability to test was limited. We could only process 750 to 1000 tests per day. Since then, the capacity has significantly increased. Now 12,500 tests a day can be processed and there are supplies in stock for more than 80,000 tests.
The criteria to get a test has loosened and random testing of people in remote areas has occurred. Social media posts also indicate nursing staff at DHBs are being tested.
With fewer cases, testing efforts are switching to assist in disease surveillance. Further details about surveillance were included in Friday afternoon’s bulk document release.
High-risk people will be offered tests, regardless of whether they have symptoms. The groups classed as high-risk include staff in quarantine hotels, international air crew, healthcare workers, people in aged residential care, essential workers and vulnerable groups.
At present our testing technology is based on the PCR test, which has a 24 to 48-hour turn-around. It tests for the presence of the virus. Advances in point-of-care tests are being watched closely. These are tests that can provide results in around an hour, rather than taking the 24 to 48 hours the current PCR tests take.
Antibody tests can give an idea of the level of immunity present in New Zealand. If you’ve been previously exposed to the virus, it’s anticipated you will have some level of immunity to the virus. It’s these tests that have been the focus of ‘immunity passport’ conversations overseas, where people who can prove they have antibodies may be allowed to return to work earlier.
However, the quick result, point-of-care antibody tests have come under fire due to high error rates. To date, New Zealand is not using these tests as there are ongoing issues with reliability.
A surveillance report suggests a laboratory-based antibody test with better accuracy than the quick result tests may be ready by June. This could be used to assess susceptibility at a national level, as well as in sub-groups “but is unlikely to provide useful information for making decisions before mid-2020”.
When cases happen can we quickly trace and isolate all close contacts?
As isolated cases pop up, finding and isolating close contacts of infected people will be key to stopping clusters emerging. New Zealand has had 16 ‘significant’ clusters of 10 or more people. The two largest are centred around a wedding in Bluff and the Marist College in Auckland. In just 24 days, the Marist cluster grew to 93 cases.
University of Otago senior lecturer Ayesha Verrall, an expert in infectious diseases and contact tracing, found gaps in the existing contact tracing system, including slow processing times and workloads that exceed the capacity of Public Health Units. Her report contained a list of targets that should be met in order to have a robust contact tracing system.
Not all of the targets have been met. Public Health Units are now equipped to trace 1000 cases and contacts within five days, but are one day off hitting a second target in Verrall’s report of isolating more than 80 percent of contact with symptoms within four days. Currently it takes five days. The Ministry of Health has not answered Newsroom’s question about whether it is able to track 80 percent of contacts.
With case numbers low and with lingering technical issues, the idea of a voluntary contact tracing app, such as Singapore’s TraceTogether, appears to have slid down the priority list.
Is a vaccine on the horizon?
A vaccine is seen by most as the best way for life to return to normal.
Usually vaccines take years to make, with four years for a mumps vaccine setting the speed record. There’s an expectation for Covid-19 this record will be beaten. It’s a moon shot, but the hope is a vaccine might be available by August next year.
To achieve that, normally sequential phases will need to be shorter, and run concurrently. Project timelines will look more like a leaning stacked tower than a gentle flight of stairs.
As soon as one phase has proven to be safe, the next phase will need to kick in. Approvals will need to be swift, and facilities to manufacture the billions of doses of vaccine will need to be built before it’s even known what type of vaccine technology will win the race. TheNew York Times has an interactive tool that shows the detail of how the timeline needs to be compressed.
Of the eight vaccines listed by the World Health Organisation, seven are in phase one and two trials. With the third phase, normally the longest, where vaccinated people are tracked over time to see if they naturally catch the virus, there are calls for what’s called a ‘human challenge’ approach. This is where vaccinated people are purposely exposed to the virus.
One of the frontrunners is an RNA vaccine. The attraction of this type of vaccine is the potential speed to market once approved. The catch is no RNA vaccine has ever been approved for use in humans. The other vaccine is a non-replicating viral vector vaccine being researched by Oxford University.
University of Auckland’s vaccinologist Helen Petousis-Harris is picking a vaccine could be approved as early as the end of the year but stresses there are no promises, saying it’s a Hail Mary of the “moon, the stars and the planets” aligning.
“It’s about everything going well and these things can fall over at any stage.”
There’s also been a call for New Zealand to join the race to create a vaccine. Even if the international vaccine effort is successful, no manufacturing facility is capable of pumping out eight billion doses in a short timeframe. A local version of a vaccine could help to sidestep a lengthy queue.
Bridging funding of $100,000 has been awarded from a Ministry of Business, Innovation and Employment’s Covid-19 Innovation Acceleration Fund to Avalia Immunotherapies. This will help researchers from the Malaghan Institute of Medical Research, University of Otago, Victoria University of Wellington, AgResearch and South Pacific Sera to continue their work of assessing local vaccine capability until a national vaccine strategy is in place.
Are any treatments showing promise?
There’s no cure for the virus, but it’s conceivable treatments could shorten the illness, or reduce the severity of symptoms and reduce fatalities. There are a wide range of treatments from antibody treatments to antivirals.
One of the most promising at present may be the antiviral medicine remdesivir, originally intended for use against Ebola. It appears to reduce the length of time a person with Covid-19 is ill from 15 to 11 days, and reduce the mortality rate from 11.6 percent to 8 percent. As yet, the preliminary results are only available through press releases – full data has not been released. The drug has not been approved for use as yet and it’s not in pill form. Daily doses are given by injection.
It’s just one of many drugs being tested, and there’s a chance pairing an antiviral with another drug in a cocktail may further improve results.
Older drugs already approved for use for other conditions are also being investigated for their efficacy against the virus. Hydroxychloroquine, which was put forward as a possible treatment early on in the outbreak hasn’t shown results encouraging routine use beyond clinical trials.
What do we understand about the virus?
To defeat a foe it helps to understand their strategies and weaknesses.
With a better answer due to better evidence always around the scientific corner it’s perhaps a little unfair to say there are no answers to the big questions. There are some answers, and there are some conflicting answers. Over time, as more studies are done, it is likely consensus will be reached for some, if not all, of the burning questions.
What does seem to be agreed is the virus is “tricky”.
What was first considered be a virus that mainly caused respiratory disease is now known to cause a loss of smell, blood clots, kidney issues and even ‘covid toes’, where capillaries become inflamed and chilblains occur.
Men seem to suffer more severe symptoms than women and obesity can be a factor in more severe cases.
Age appears to play a role. In the United Kingdom the median age of hospital patients is 72. At first it seemed children had milder symptoms to adults, but now a number have suffered something similar to toxic shock, referred to as a “multi-system inflammatory state”.
Immunity is another grey area. It’s expected people who recover from an infection will have some level of immunity to the virus, and an experiment in monkeys has shown reinfection did not occur. A fear that people were able to be reinfected has been dispelled for now. Recovered patients in South Korea who tested positive after returning negative tests were thought to be showing virus fragments from their previous illness, not a new infection.
How long any immunity might last is a big unknown. Short of inventing a time machine to travel into the future, it’s a wait-and-see question. Conservatively it is hoped immunity could last for at least six months and hopefully up to a year.
When a person is infectious is one area where enough studies have shown similar results. The viral load seems higher in the early stages of infection. How infectious a person is prior to symptoms showing is less clear but a picture is emerging that people can spread the virus before they have any tell-tale symptoms.
Another area of debate is the widespread use of face masks. A review published on the Ministry of Health website says there is no conclusive evidence for or against the efficacy of widespread face mask use by the public. Some countries have adopted a policy of public mask wearing while others have not.
In New Zealand, advice for home carers changed on Wednesday after a long battle. Previously, workers performing up-close-and-personal tasks with elderly and disabled people in their homes were told they didn’t need masks. This translated to DHBs not supplying them with masks, and workers washing and reusing the single-use masks they owned.
The change came a day before announcements about what Level 2 might look like were made. Prime Minister Jacinda Ardern explained hairdressers would be allowed to resume seeing clients but with appropriate PPE “because of the close proximity you have with your customers throughout the day and because we want to protect you and your client”.