Summary
As COVID-19 persists into its fifth year in Aotearoa New Zealand (NZ), we need to recognise that this pandemic is very different to expectations and adapt accordingly. Evolving variants are driving ongoing waves of infection, prolonging the pandemic's impact. It remains a leading cause of hospitalisation and death, particularly in older populations and those with underlying illness. But its largest health impact may be Long Covid because it is relatively common after acute infections in all ages.
This ongoing disease burden demands a proportionate response. It would probably be more efficient to use an integrated strategy that combines the response to Covid-19 with influenza and other respiratory infections. The core of this strategy is high vaccine coverage, testing and self-isolation when sick, and measures to reduce transmission in critical indoor environments. Equity is central. Wishful thinking won't transform Covid-19 into a mild illness; evidence-informed responses are necessary to combat this ongoing threat.
February 28 marks four years since Covid-19 was first reported in Aotearoa New Zealand. Many of us are probably surprised this virus is still causing a pandemic.
The World Health Organization refers to Covid-19 as a continuing pandemic. As Scientific American put it recently, it “has been the elephant in every room — sometimes confronted and sometimes ignored but always present”.
It wasn’t meant to be like this. The main wave of the 1918 influenza pandemic swept through New Zealand in eight weeks, killing 9,000 people – almost 1% of the population.1 Then it was largely gone, returning as a new seasonal flu virus.
In doing so, it defined how pandemics were expected to behave. This model was written into pandemic plans and collective thinking across the globe.
But Covid is still circulating four years after NZ reported its first case, and more than two years after the Omicron variant arrived and infection became widespread.
Constantly present, it is also occurring in waves. Unexpectedly, the current fifth wave 2 was larger than the fourth,3 suggesting we can’t rely on the comforting assumption that Covid will get less severe over time.
Unpredictable evolutionary shifts
These waves are driven by the interaction of the organism (SARS CoV-2 virus), the host (human characteristics such as immunity and behaviour), and environmental factors (such as indoor ventilation).
Continuing viral evolution is a major contributor to the changing dynamic. The virus has demonstrated an ability for large, unpredictable evolutionary shifts that dramatically alter its genome and spike protein.
The result is an enhanced ability to evade prior immunity and infect more people. This jump was seen with the highly mutated BA.2.86 subvariant in mid-2023.4
Its offspring, JN.1, has acquired additional changes and is causing such a wave of new infections it could potentially be the next variant of concern, with its own Greek letter. It is now driving epidemic increases across the globe, including in New Zealand. This dominance by a single subvariant takes us back to the first year of Omicron in 2022.
Under-counting the pandemic impact
The pandemic continues to have a large, visible health impact. It is a leading cause of serious illness and death, mainly in older populations and those with existing long-term health conditions.
In 2023, it caused more than 12,000 hospitalisations and 1,000 deaths in New Zealand.2
But Covid-19 also has an important and largely unmeasured burden of disease as the cause of long Covid , which may become its biggest health impact.5 A growing number of studies are describing an estimated incidence of long Covid of 5% to 15% of all infections.
For example, a recent large study of almost 200,000 Scottish adults reported that, after adjustment for factors that might confuse the results, long Covid prevalence following an infection was 6.6% at six months, 6.5% at 12 months, and 10.4% at 18 months.6
These findings illustrate an important feature of long Covid : recovery can take two years or more, with symptoms that fluctuate over time.7
An integrated respiratory disease strategy
New Zealand now needs a strong, integrated response to Covid -19 and other respiratory infections.
The major pandemic interventions have not changed: vaccination, public health and social measures to prevent infection, and antivirals for more vulnerable groups. The evidence has firmed up that long Covid risk is reduced by vaccination,8 but research is less certain for antivirals.
But growing pandemic complacency from political leaders and the public has changed things. Some of this apparent indifference can be put down to understandable fatigue with response measures. But it remains dangerous in the face of a continuing pandemic.
One way to keep a focus on prevention and control would be to include these measures in an integrated respiratory infectious disease strategy.9 This would combine Covid -19 control measures with those used to protect against influenza, respiratory syncytial virus (RSV), and other respiratory infections.
Measles could be added to the list, given the rising threat to New Zealand 10 from a global resurgence of the disease.
This integrated strategy would include vaccination, promoting testing and self-isolation when sick, and measures to reduce transmission in critical indoor environments such as healthcare, public transport and education settings.9
Such a programme would need to be supported with community engagement, education, surveillance and research.
Structural inequalities mean Māori, Pacific peoples, and those living in relative deprivation, are less vaccinated, less protected from infection, less tested and less likely to have antivirals.
Consequently, they are more likely to be hospitalised and die from Covid-19. These inequities are currently not being systematically tracked and acted on.
Ignoring it won’t make it go away
As we enter the fifth pandemic year, we need a change in thinking about Covid-19. This infection has pathological features in common with the other severe coronaviruses (SARS and MERS).11
It is wishful thinking to imagine it will suddenly transform into a common cold coronavirus. As a recent review article concluded12:
Transition from a pandemic to future endemic existence of SARS-CoV-2 is likely to be long and erratic […] endemic SARS-CoV-2 is by far not a synonym for safe infections, mild Covid-19 or a low population mortality and morbidity burden.
In the face of this continuing pandemic threat, we need a response that is evidence-informed rather than evidence-ignored.
Michael Baker, Professor of Public Health, University of Otago; Amanda Kvalsvig, Associate Professor, Department of Public Health, University of Otago, and Matire Harwood, Associate Professor, Department of General Practice and Primary Care, University of Auckland, Waipapa Taumata Rau
This article is republished from The Conversation under a Creative Commons license. Read the original article.
What is new in this Briefing
- Previous pandemics have not prepared us for Covid-19 which is continuing to cause pandemic waves four years after it arrived in NZ.
- Covid-19 is still causing more hospitalisations and deaths than any other infectious disease in NZ, particularly in older populations and those with underlying disease.
- Its most important health impact may be long Covid, which is a relatively common post-infection complication across all age groups.
Implications for public health policy and practice
- The continuing threat of Covid-19 requires a proportionately strong response, which could be efficiently integrated with other important respiratory infections such as influenza.
- The core of this strategy is high vaccine coverage, testing and self-isolation when sick, and measures to reduce transmission in critical indoor environments such as healthcare, public transport, and education settings.
- This integrated strategy needs to be supported with community engagement, education, surveillance, and research.
