How will the pandemic end?
It’s a question that few have a definitive answer to, though plausible ideas abound.
Jacinda Ardern says Covid-19 will become endemic and require repeat vaccinations, like the flu.
Epidemiologist Michael Baker suggests the world might eliminate the virus, given the efficacy of the vaccines developed to date. If, however, global efforts fail, then he too concedes that it could come to resemble influenza.
“The challenge now is to ensure as many New Zealanders as possible receive these vaccines. Until that time, the country needs to maintain its elimination strategy, although there is keen interest in taking a more nuanced risk-based approach to relaxing controls at the border.”
– Dr Ashley Bloomfield
In an editorial published in The New Zealand Medical Journal on Friday, Director-General of Health Dr Ashley Bloomfield says that, until as many New Zealanders as possible are vaccinated, we need to stick to maintaining vigilance at the border.
“The challenge now is to ensure as many New Zealanders as possible receive these vaccines,” he writes. “Until that time, the country needs to maintain its elimination strategy, although there is keen interest in taking a more nuanced risk-based approach to relaxing controls at the border.”
However, even if Covid-19 does become endemic globally, there will be a point when New Zealand will want to open its borders. Presumably, widespread vaccination would mean the virus could no longer rack up enough hospitalisations to overwhelm the health system – the primary threat from Covid-19 – but we will still have to deal with what it means to stop eliminating Covid-19.
What happens when the first Covid-19 case arrives in the community? What about the first hospitalisation? The first death?
Ending the pandemic
It is not yet a foregone conclusion that the pandemic will end with Covid-19 becoming just one more endemic coronavirus – several others circulating among humans now cause the common cold.
Baker, in particular, is hopeful that the efficacy of the vaccines – numerous jabs have proven to be more than 90 percent effective at preventing severe infection – would make it easier for the rest of the world to attain New Zealand’s Covid-free status. Even the countries that have been worst-hit by the pandemic could yet recover, he says.
“It’s been done for smallpox, it’s very close to being done for polio. In many ways, it will come down to the basic biology of infection, the effectiveness of the vaccine and the cost-effectiveness. But we might just conclude that actually it’s more efficient to continue with a zero-Covid approach.”
Baker also references the original SARS virus, which was effectively eliminated through public health measures.
“One scenario could be regional elimination or even global eradication as we saw with Sars,” he wrote in an article for the Guardian in late January.
Philip Hill, a colleague of Baker’s at the University of Otago and co-director of the Centre for International Health, told Newsroom he wasn’t so sure the world could eliminate Covid-19.
“We’ve only eliminated one pathogen, remember? So you have to assume we’re not going to eliminate this one,” he said.
Jacinda Ardern seems to agree with Hill, telling her caucus in January that, “Our goal has to be to get the management of Covid-19 to a similar place as we do seasonally with the flu. It won’t be a disease that we see simply disappear after one round of vaccinations across the population.”
That may have been informed by the view of Director-General of Health Ashley Bloomfield, who told reporters later that month that it would be difficult to globally eliminate or eradicate Covid-19.
“Because of the nature of these viruses, it’s more likely to be endemic. We’ve successfully eliminated smallpox, we’re close to eliminating polio, but there’s very few diseases that it’s possible to eliminate or eradicate. These coronaviruses and influenza viruses do tend to become endemic.”
When we stop eliminating it
If Bloomfield is right, that means New Zealand will reach a stage when we stop eliminating Covid-19. That is, we no longer attempt to stamp out every community case because these cases don’t threaten to overwhelm the health system.
In a population without any natural immunity to the coronavirus and with insufficient measures to stop the spread – hand washing, mass masking and, for larger outbreaks, lockdowns – it can spread quickly enough to send large numbers of people to hospital. Around the world, countries have expressed confidence in their ability to handle rising case numbers before abruptly reversng course when the caseload puts their health systems on the brink of collapse.
In New Zealand, that brink is rarely far away. In March, we had just 176 intensive care beds, meaning sustained and widespread transmission would overwhelm our hospitals much faster than those of Italy or Spain, which both have many more ICU beds per capita.
Elimination, therefore, emerged as the obvious choice. The benefits are clear: We live under fewer restrictions than most of the rest of the world, we have enjoyed a faster recovery and we have seen far fewer per capita cases, hospitalisations and deaths.
To say, therefore, that we will at some stage abandon elimination is not to imply it was the wrong strategy in the moment. But as new, effective vaccines remove the threat of Covid-19 – a widely-vaccinated population is unlikely to experience an outbreak that could overwhelm our health system – the elimination approach may no longer be needed.
“There will be a point when we need to adjust our approach from an elimination strategy,” Bloomfield said.
“If we think of other diseases like measles, where we have achieved elimination status, that is also very dependent on what is happening internationally. And hence the comments from the Director-General of the World Health Organisation, actually, every country needs the whole global population to achieve a high level of vaccination before we can really get back to what will be a new normal, but a different sort of world with Covid-19.”
Baker and Hill both said the end of elimination could come as a result of a specific, strategic choice or the result of other factors.
That sort of thing will either happen strategically or we’ll drift into it,” Hill said. “The key thing is the [vaccination] threshold and who’s going to make the first decision on that and what they’re going to do when there’s the first death.”
It’s not just about deaths, however. Baker raises the issue of so-called ‘Long Covid’ – long-lasting symptoms from Covid-19 infections including fatigue, shortness of breath and inflammation. For some people, Long Covid has been debilitating. Studies suggest that a majority of those hospitalised with Covid-19 and a smaller percentage of those who have mild or asymptomatic infections will develop Long Covid.
It remains unclear whether vaccines might prevent Long Covid or only severe disease.
There’s also the need to consider mental health and social impacts of opening the borders to a disease which New Zealanders have spent the past year assuming they will never encounter.
“Are we going to freak out when cases do come in? Which of course they will,” Helen Petousis-Harris, an associate professor in vaccinology at the University of Auckland and the chair of the World Health Organisation’s Global Advisory Committee on Vaccine Safety, told Newsroom.
“You’re going to get occasional cases and, occasionally, someone will get severely ill and require hospitalisation. But it’s not going to be something that is going to over-burden your health system.”
Sarb Johal, a clinical psychologist who has repeatedly spoken about mental health during the pandemic, said the adjustment to ending elimination would require careful finessing by the Government.
“I’ve seen some narratives being developed around how this is an annual threat at a particular time of year. Already the vaccine manufacturers are talking about booster shots. Maybe this is a socialisation of, actually this is going to be an endemic threat around the world for quite some time to come,” he said.
“There’s a big socialisation narrative around, what can the Government do in order to protect us and how can we participate in that? And what do we need to do to in terms of personal responsibility to stop and check the spread?”
Exactly how people would react would also depend on how threatened they felt by opening the borders.
“It would very much depend upon what stage the global cycle was at and our place in it. If they tried to do that now, it would be very difficult, because I’m not sure whether it would be perceived that we have taken all the protective measures that we would need to take before that happened,” Johal said.
Either way, however, “the reality is we’re going to be dealing with a world with Covid still in it.”