Q&A: What Omicron wave means for NZ's Long Covid risk

Long Covid is thought to be a legacy of one in 10 symptomatic infections with Covid-19. Photo / 123RF

With New Zealand riding another Omicron wave that could soon peak with more than 20,000 daily cases, the risk of Long Covid to our communities looms all the larger. Science reporter Jamie Morton asked University of Auckland immunologist Dr Anna Brooks about the potential lingering fall-out of this winter surge.

Long Covid is a constellation of long-lingering, post-infection symptoms. How are we defining it currently?

As defined by the World Health Organisation, we consider it as ongoing symptoms that persist or worsen three months after infection.

Symptoms can vary widely, but unwavering fatigue, shortness of breath and cognitive impairment – which we know better as brain fog – are still very much the core ones.

Long Covid can mean, that even after three months, your previous energy levels haven't returned and you're unable to have the normal life you once had – whether that's not being able to return to work, or just struggling with daily activities.

For some, depending on severity, it can mean their whole world is turned upside down by this debilitating, life-changing illness - which there is currently no treatment for.

Unfortunately, there are still inconsistencies in receiving an official diagnosis, although there are clinical pathways in development that GPs should be able to use.

Who's considered most at risk?

We know there are some factors that come with increased risk of Long Covid, and they include being of older age, having a higher body mass index, having an underlying chronic illness, or having been admitted to hospital with acute Covid-19.

However, Long Covid can occur following severe, mild, or even asymptomatic infection – so really, anyone is at risk.

We know that Māori and Pasifika populations are at risk because these groups are over-represented in case statistics, and this reflects wider, complex problems like health inequity.

But incidence is still fairly spread across different cohorts. There have also been studies to shown that more women are affected, but the reason for this demographic trend isn't clear, and we need to learn more about this.

Part of that could be that women may be better at seeking help than men and so these cases are detected more.

What do we know about the current prevalence of Long Covid in New Zealand?

A recent survey out of the US Centers for Disease Control and Prevention (CDC) indicated as many as one in 13 Americans – or 7.5 per cent of their population – still have Long Covid after infection.

But in New Zealand, we just don't know.

If we consider Long Covid comes with 10 per cent of symptomatic infections, and that perhaps half of our population has been infected, we can do a rough, back-of-the-envelope calculation to look at what that number might be.

But even if you strip it back to 1 per cent of the population, that's still a huge number.

This is why New Zealand needs a tracking system to get a true sense of the scale of the situation, and so we can get some hard numbers.

It would make sense to incorporate this into our current reporting system, however given this hasn't happened yet, perhaps this might need to be carried out independent of the Government.

How might this building Omicron wave make things worse?

This is New Zealand's first time facing a massive outbreak with the most minimal public health mitigations in place.

We really need a "Vaccines Plus" approach to reduce the potential long term harms from infection.

Even vaccinations aren't going to save us all from symptomatic infection, because we know that the BA.5 subvariant can more easily evade our immune protection.

Another wave likely just bumps our collective risk of Long Covid up higher – but the key thing this time is many of us have waning immunity and complacency has crept in.

If you're symptomatic and have a rough time while infected, this could mean either your symptoms are due to your immune system putting up a good fight to eliminate the virus, or your symptoms occur because the virus is harming you.

We don't really have any way of telling the difference.

Either way, if the virus has a chance to cause harm, this is likely when your risk of Long Covid starts.

Our best chance of lowering risks is to avoid infection. The next best chance is to be up to date with vaccinations.

But the more people we have getting infected, the greater chance we have of seeing a lot more Long Covid cases.

We're hearing a lot about hospitalisation rates going up, but Long Covid and other health complications are going to be a risk for anyone who gets Omicron – so it is critical that we keep long-term impacts front of mind, too.

People battling away in their own homes, sick and then potentially not recovering is still a really big issue right now.

As well, we know that many cases are still going unreported.

Dr Anna Brooks of the University of Auckland is studying the immune dysfunction experienced by Kiwi "long-haulers". Photo / Supplied

Whether that's because people have the pressure to continue to work, have no sick leave left, to avoid getting stuck while they're on holiday and need to get back on a plane, all of these things likely come into play.

Will people catching Covid-19 a second or third time be at higher odds of developing Long Covid?

Reinfection is obviously best avoided – but it's not yet clear that it can raise the risk for everyone. We also need to be mindful that we have other winter viruses circulating too – which may also impact the risk.

A recent US study suggested those with reinfection had at least one condition linked with Long Covid that still lingered on even six months afterwards.

But, while there's been a tendency to say that the more infections you get, the higher risk you have of Long Covid, the fact is, we still don't know.

What should people do to reduce their risk?

Firstly, take this wave seriously: I think the complacency out there is very real.

Mask up – high quality is best, but at least make sure it fits you well, and be conscious of the fact this virus is airborne.

If you wear a mask into a crowded place, but take it off to eat and drink, you're still at risk, especially if indoors and not well ventilated.

A lot of it's about respecting people around you as well, especially those in our society who are clinically vulnerable and I get the sense this has all gone out the window given mask use has been dropping.

If you go anywhere where masking is required, the count of people actually wearing them, at least consistently, is alarmingly low – especially in social settings.

Then there is the fact that indoor events or gatherings don't actually require mask use at all – they are only recommended.

Until such guidelines are strengthened, and mask wearing becomes second nature, we can expect cases to keep escalating, and so too will the risks of Long Covid.

Vaccination and boosting is still important – but it's more critical in protecting you from severe illness, and it's not going to be enough to prevent some of us from developing Long Covid.

If you or someone in your household becomes ill, get tested, and stay home.

And if you do get Covid-19, the best thing to do is to take it easy and rest as much as possible. Don't try to exercise too soon or push through it.