Nadene Ghouri has had Covid-19 four times and doesn’t want to catch it again. Her first encounter with the virus was in the early days of the pandemic while living in the UK, and it left her struggling with the post-viral effects of long Covid.
“Basically, I lost a year of my life,” she recalls. “I couldn’t walk down the street without being out of breath. My son, Gilbert, was still a baby and I’d have to call my husband at work and get him to come home because I couldn’t even pick him up – that’s how weak I was.”
She was still based in the UK when she succumbed a second time and had the classic symptoms of fever, fatigue, shakes and aches. By her third bout, the family had moved to New Zealand and she managed to get a doctor to prescribe antiviral medication, which helped. Unfortunately, working in a busy open-plan office, the Auckland-based journalist couldn’t avoid catching Covid-19 a fourth time. She is now convinced that she is prone to reinfection, so when her husband tested positive just before Christmas, she isolated him in a bedroom.
“If he had to come out to use the bathroom or kitchen, he wore a mask and sanitised after himself,” says Ghouri. “Thankfully, I managed not to catch it.”
Although she no longer has those more debilitating long Covid symptoms, the virus has had a lasting impact in other ways.
“It’s changed my life and I think those changes will be permanent,” says Ghouri. “Just the thought of getting Covid again is really scary. Because I feel like I’ve got this target on my back, I try to avoid crowded and enclosed spaces. And I find it hard not to get angry when I have conversations with people who don’t take Covid seriously. Even now, if I over-exert myself or get very tired, I’ll feel my heart fluttering and get dizzy, then have to lie down.”
We have now entered the fifth year of the pandemic and although waves of new variants keep coming, most of us are no longer taking the sorts of precautions we once relied on. Dr Amanda Kvalsvig, an epidemiologist at the University of Otago’s public health department, understands the urge to move on and put Covid-19 behind us. “We all want the pandemic to finish and to get back to how we were in 2019,” she says. “It is such a strong pull that it actually shapes our thinking. But this pathogen is still causing illness, hospitalisations and death, and it is still a disruption to society. No amount of wishful thinking is going to make it go away, so we need to deal with it.”
Strategy missing
An estimated 1000 New Zealanders died of Covid last year and more than 12,000 were hospitalised. In the last week of March, 3399 new cases were reported and seven deaths were attributed to Covid-19, taking the total number of deaths to 5922. Kvalsvig is among a group of scientists calling for a comprehensive strategy to mitigate not only the next phase of the pandemic but other respiratory infectious diseases including flu, respiratory syncytial virus (RSV) and measles.
“There is no one magic bullet, but we do have a toolkit of different ways to prevent, control and mitigate the impacts of these pathogens as we are going about our normal lives. When those tools work together in an integrated strategy, that is when you start to see the results.”
Improving air quality in enclosed environments where people congregate is a key part of the proposal. Kvalsvig maintains we need to starting thinking about air like we do about water. Dirty water is linked to transmission of diseases such as cholera, dysentery and typhoid, and in the 19th century the provision of clean drinking water played a large part in the public health revolution.
“We need to be breathing clean air in the same way we need to drink clean water,” she says. She carries a CO2 monitor to check how well ventilated spaces that she occupies might be. “I’m getting a sense now of where the inside air quality is good and where it isn’t. And it’s terrible on buses.”
As well as ventilation on public transport needing improvement, she argues workplaces aren’t doing enough to ensure employees don’t get sick. “We have regulations about workplace safety, but there’s a huge blind spot at the moment with respiratory infections, including Covid-19.”
Hospitals are also a concern. Ironically, 100 years ago, they understood the importance of fresh air, so wards had windows that were kept open. That was forgotten over the past century and hospitals now tend to be airless, overheated places where airborne diseases can be far more easily transmitted.
“People who are immunocompromised, such as cancer patients, are facing this terrible dilemma of knowing they are at risk while inside a hospital because they might catch Covid and the outcome could be very serious for them,” says Kvalsvig.
Schools are another location where air purifiers would help minimise the spread of viruses. Although most children will experience a milder Covid-19 infection, inevitably they take the virus home and pass it on to family members who may be more seriously affected.
“When you look at the wastewater [testing] graphs, you can see exactly when the term started,” says Kvalsvig. “We know that Covid is spreading in schools. Before the pandemic, we knew that a lot of other infections, such as flu, RSV, measles and chickenpox, spread in schools. They are such hubs in their community and, when there is an outbreak, they are accelerants.”
Associate Education Minister David Seymour’s push to raise school attendance levels by reducing sickness-related absences – with fines a possibility for persistent non-attendance in some circumstances – worries Kvalsvig. The Act leader told RNZ last week: “We accept Covid happened but that’s largely subsided now, and yet we still have a doubling of the number of kids kept home for health reasons.” The government plans to update public health guidance “to help schools and parents to decide if a student is well enough to attend school” and publish weekly attendance data.
Kvalsvig says both health and education suffer when children go to school sick. As recently as February, a Covid outbreak forced the closure of Rangiora High School in North Canterbury. “It’s hard to understand why the [associate] minister is proposing this course of action at a time when New Zealand is at high risk of a national measles epidemic.”
Measles can begin with nonspecific symptoms such as fever, a runny nose or red eyes, she says. “Measles outbreaks are highly disruptive for schools and infection can be disastrous for some children, resulting in hospitalisations and even deaths.
“At the moment, the advice should be exactly the opposite of what he is proposing. Instead, parents and schools should be extra careful about ensuring that sick children can stay home and they should know they have the full support of government to do so and keep school communities safe.
“No matter how much everyone wants it to be over, we are still in a pandemic. The country is now experiencing a fifth wave that is larger and more prolonged than its fourth wave, and New Zealanders are being exposed to Covid-19 infection and reinfection all year round. A far more realistic approach would be for New Zealand to adopt clean indoor air standards.”
Brain & heart damage
Already, it is clear that children aren’t immune to long Covid. What is less certain is exactly how repeated infections with the SARs-CoV-2 virus might be affecting the developing brain.
There is strong evidence to show that Covid-19 does have an impact on the brain and nervous system, at least in the short term. Last year, a large imaging study, published in Nature, compared the brain scans of 785 participants aged over 50 before and after mostly mild infection and found changes in the parts of the brain that affect memory and smell. More recently, another study, published in the New England Journal of Medicine, identified a decline in IQ after Covid-19 infection, even among milder cases. Reinfection caused a further drop in brain power.
The SARs-CoV-2 virus doesn’t only trigger inflammation in the brain, it can be damaging to heart health, affecting the lining of the blood vessels, and in some patients can lead to abnormal blood clotting. There is science to show that, at least for older people, a Covid-19 infection increases the risk of cardiovascular diseases.
Researchers are also investigating a link between Covid-19 and diabetes. The virus seems to be a trigger for type 1 diabetes and there is mounting evidence that it increases the risk of developing type 2 diabetes, with that risk persisting through the era of Omicron and its variants. Add to that the knowledge that each repeat infection increases your chance of ending up with long Covid, and it seems reasonable to avoid multiple bouts of illness.
“People might expect to get flu twice in a decade,” says Kvalsvig. “With this virus, some people are getting it twice a year.”
The strategy she and her colleagues would like to see us adopt to change that includes measures many of us will be familiar with, including self-isolation while sick and mask-wearing. As a deaf person, Kvalsvig has good reason to dislike masks. Not being able to see people’s faces when they speak makes it more difficult for her to understand them. Still, she recommends wearing one in crowded and poorly ventilated indoor areas. “I wear mine in work meetings because I know there are lots of cases around and I also know that I do not want to get long Covid; I’m very clear about that.”
The World Health Organisation (WHO) defines long Covid as people still experiencing symptoms three months after infection that can’t be explained by another illness. With a wide range of symptoms, including brain fog and extreme fatigue, it is estimated from recent studies to affect 4-14% of sufferers, according to the Public Health Communication Centre Aotearoa. Latest census data from the US shows that one in four Americans who were infected with Covid-19 went on to develop it, with younger adults having far higher rates than the older demographic.
Nevertheless, Queensland’s chief health officer, Dr John Gerrard, recently argued it was time to stop using the term long Covid altogether. He said it appears to be a severe and distinct disease only because of the huge numbers of infections during the pandemic, and that the term implies there is something unique about it.
Vaccine funding up in the air
Whatever you choose to call it, vaccination not only lowers the risk of severe infection but also the chance of post-viral symptoms, according to a study published in the Lancet in January. This is why, in a new briefing paper on long Covid, Kvalsvig and a group of experts are pushing for Covid-19 vaccines to be more equitably available to younger groups.
Vaccination has also been shown to be highly effective at preventing serious cardiovascular complications for up to a year post-infection. The science even suggests it may provide a protective effect against diabetes. Meanwhile, a study of more than 99 million people by researchers working as part of the Global Vaccine Data Network confirms that the benefits of vaccines for Covid-19, including the Pfizer version used by most New Zealanders, outweigh any risk of rare side effects including myocarditis (inflammation of the heart muscle) and pericarditis (swelling of the thin tissue surrounding the heart).
Covid-19 vaccines are funded via Pharmac for those who are eligible. They remain free for everyone aged five and over, or from six months old for those children with severe health problems. Additional booster doses are available for those aged 30 and over, and younger people who have complex health needs or are pregnant. Others aged 16-29 can have one additional dose.
Funding for the current vaccine programme, along with free rapid antigen tests and antiviral treatments, comes to an end on June 30. How things will work beyond that date is being considered as part of Budget 2024, to be released on May 30.
The latest version of the Pfizer vaccine made available in New Zealand last month has been modified to protect against the Omicron subvariant XBB 1.5, which is the one that was making us sick last year. The dominant strain of this summer’s wave has been JN1, which is estimated to have accounted for at least 93% of recent cases. So, is there any point in getting boosted again?
“Covid is falling into a similar pattern to flu, where you’re getting smaller strain changes,” says Dr Nikki Turner, of the Immunisation Advisory Centre. “Yes, they’re evolving, but they’re pretty similar. You can’t update a vaccine all the time and nor do you need to. It’s still expected to be effective against JN1 because it’s not that far removed from XBB. But you’re getting small incremental gains, not dramatic gains, from the newer vaccines.”
Turner’s expectation is that Covid-19 here will fall into a seasonal pattern, as it has elsewhere in the world. Then, the role of the vaccine will be similar to that for flu, which is funded for those at high risk and offered before winter for an immunity boost.
“Because there is so much world immunity now, the virus has less opportunity to mutate as rapidly as it has done. We’re not there yet, but I would expect it to fall into the normal pattern of a coronavirus.”
Waves of reinfection
Not everyone is convinced Covid-19 will meet expectations and settle down. In February, the WHO’s lead Covid official, Maria Van Kerkhove, told Scientific American we are still in a pandemic and the virus is here to stay. One of the scenarios she is planning for is a new variant that is highly transmissible, more severe and even better at evading the immune system. She has warned against complacency.
Modeller Michael Plank, of the University of Canterbury, says waves of infection are part of a natural cycle. After a large number of people have been infected, they will be immune for a period of time, then that immunity fades and another variant comes along, leading to reinfection.
“This is not going to disappear,” he says. “It will continue to evolve and be with us for the foreseeable future.”
It remains to be seen what kind of stable long-term pattern will be established and whether Covid-19 will become a winter virus. Quite possibly, it will remain with us year-round, with cases rising as schools and universities go back or during periods when there is an influx of international tourists. Still, Plank isn’t so convinced about the need for more than we are already doing to manage its impact.
“I think the vaccines and antivirals we have are the things that give us the biggest impact on this virus. Some of those other things – masks, indoor air quality – I’m not saying we shouldn’t do them … but it’s not clear to me that it’s going to make a big dent in numbers.”
As a mathematician, Plank is interested in the effective reproduction number – the average number of people that a single infected person will pass Covid on to. “If we took you to a population of humans on Mars who had never been exposed to the virus, you would infect 5-10 other people. But we’re not in that situation. People have immunity, which means we get a lot less infections per person than you would in a population with no immunity.
“Immunity is the biggest factor that is controlling transmission rates.” That means if we make an intervention, such as masking, it reduces the number of infections, but in doing so reduces the amount of immunity in the population. And over time, that reduces the overall benefit of the intervention.
Plank says the effective reproduction number has been hovering between 0.8 and 1.2 in New Zealand, “so that tells me that 80-90% of people at any one time have some immunity that is preventing them from getting infected.”
What he would like to see is a clearer strategy for vaccination and boosters. He believes it would make sense to have an annual booster that is given with the flu jab. “If you’re in a particular age group or meet the criteria, that would at least make it easier for you to know that it’s time to get vaccinated, whereas at the moment it’s all a bit piecemeal.”
Cross-infection
Although being infected with Covid-19 might give a degree of immunity for a while, University of Auckland cellular immunologist Anna Brooks is concerned about the interplay of the virus with other potentially severe illnesses such as flu and RSV, and is particularly worried about children who have relatively low vaccination rates. She talks about a “cycle of vulnerability”.
Brooks has been in touch with people like Nadene Ghouri who have been infected with Covid-19 several times. “I’ve worked with so many of them and it’s heartbreaking. Every time they get it, they’re sick and bedridden. I guess those people will be clinically defined some day as being Covid susceptible.”
If you’re a reasonably fit and healthy person, you can expect to catch Covid-19, be sick for a short while, then start to recover until gradually your immune system will go back to your own individual baseline. But what if you’re still on that path to immunological recovery and you get Covid again? What if you are exposed to another infectious respiratory illness before you have tracked back to your normal baseline? The cumulative effects could be much worse and potentially trigger a longer-term health problem.
“I think what is protecting us is that we’re out of sync with the rest of the world in a good way,” says Brooks. “So, as the new variant hits and creates havoc during winter in other countries, we get it in summer [when we’re not being exposed to lots of flu and RSV]. We’re not supposed to get respiratory viruses in summer, but we have followed that pattern twice.”
Future pandemics
Hopefully, RSV immunisation is on its way. Queensland and New South Wales are joining Western Australia in inoculating infants with the long-acting monoclonal antibody Beyfortus (nirsevimab). In New Zealand, another RSV vaccine is being assessed by Medsafe.
Kvalsvig has been giving some thought to how we could develop and assess a strategy that will put us in the best possible shape to face future pandemics.
“If we can bring the winter [Covid] levels down towards the summer levels, and then down to summer school holiday levels, at that point we’ll know we have a reasonable level of preparedness for the next respiratory pandemic. We’ll know that if a novel pandemic virus gets through the border, we have a reasonable chance of stopping it from running straight through our communities.
“We can continue to tweak these measures every winter until we have a really good set of protections.
“And the best thing about that is we get the benefits right away. Reduced illness, hospitalisations and deaths, and also reduced time off work and school: once New Zealanders experience that, they’ll never want to go back.”
Canary in the coal mine
With reporting of Covid cases plummeting, a reliable surveillance system is called for.
With Covid-19, there is still much we don’t know. Why do some people seem to evade catching the virus while others get it every time a new subvariant sweeps through? What impact will post-viral symptoms have on sufferers in the longer term? How far away is an accurate and accessible test we can use to check our own immunological fitness? How long before another infectious disease threatens a new pandemic, and how severe will that be?
Having measures in place for the things we don’t yet know about takes us back to the “vaccines plus” approach advocated by the University of Otago and other public health experts at the peak of the country’s pandemic response. It combined high vaccination coverage with effective public health and social measures.
A key pillar of this approach was surveillance, but fewer people are bothering to test for Covid-19 or report the result now that we have returned to our pre-pandemic lives. A better estimate of case numbers is now coming from clues such as wastewater testing and hospitalisations.
Otago epidemiologist Dr Amanda Kvalsvig and her colleagues propose setting up sentinel sites in communities around the country to monitor infections and test for viruses in a systematic way. This would be a useful resource in improving our understanding of how respiratory infections spread, and would provide an early warning of new outbreaks and epidemics.
“It’s the canary-in-the-coal-mine idea,” says Kvalsvig. “If you have places around the country where there is regular testing going on, and you see that those people are testing positive, then it suggests others are, too.
“Surveillance is a bit like a jigsaw puzzle,” she adds. “You collect lots of different types of information and put them together to form a picture. I would also love to see much better reporting about school sickness absenteeism because that would be an important early signal of something going on. And once you’ve put the puzzle together then you need to reflect it back to the population – tell people what is going on so they can take action.”
To read more about Long Covid, go here.