When will the Covid-19 pandemic end? That’s the question on everyone’s mind.
There are two main ways a pandemic can end - either the infectious disease gets eradicated or it becomes endemic.
An endemic illness is always circulating in society, but is managed by the immunity created when people either get sick and survive, or are vaccinated.
Amanda Kvalsvig, an epidemiologist at the University of Otago, says in past pandemics, such as the 1918 flu, the only option was for the virus to spread until it became endemic.
In the two years that the 1918 flu spread, it killed 50 million people around the world.
We now have ways to control illness, Kvalsvig says.
Vaccines, properly ventilated spaces, and the ability to genomically test and track the spread of the virus. These are all tools that can be used to slow or stop the spread of illnesses completely.
This leaves the world at a tipping point as to how this pandemic will end, Kvalsvig says.
“The pandemic will end either because we choose to end it or because we choose not to and instead move by default to a situation of ongoing transmission.”
Jemma Geoghegan ,a biologist and virologist at the University of Otago, who studies the way diseases evolve, says we’ve likely passed that tipping point, and the most probable way to end this pandemic will be its transition to an endemic illness.
“I can’t see how there is going to be a different ending to this,” Geoghegan says.
“In certain pockets of the world, eradication might be achievable but we certainly don't have a global approach to dealing with pandemics and that is quite clear. I can’t see a worldwide eradication programme happening.”
Both Geoghegan and Kvalsvig noted that just because a disease is endemic, does not mean it will not be severe.
Some of the most deadly illnesses on the planet are endemic, including malaria, tuberculosis, and influenza.
In 2020, as many as 650,000 people died from both malaria and influenza, and 1.5 million people died from tuberculosis.
In the same year, the Covid-19 pandemic killed nearly 2 million people, and 3.5 million more since.
If the likely end to the Covid-19 pandemic is a transition to an endemic illness, when will that happen, and what will that look like in Aotearoa?
Bringing the reproduction number to one
The most important factor in transitioning out of a pandemic is stopping the widespread transmission of the illness.
We track spread using the reproduction number, which represents how many people an infected person willl transmit the illness to.
For example, if the number is seven, an infected person will spread the illness to seven people.
The three major strains of Covid-19 have gotten better at spreading which has led to an increase in the reproduction number, Geoghegan says.
Across the world, the original strain had an average reproduction number of 2.79, Delta had a number of 5.08, and Omicron is showing reproduction numbers between 7-14.
For an illness to be endemic, the average reproduction number needs to be one or below.
“If our reproduction number is under one, then the virus will always die out. If it is above one the virus will always spread.”
In Aotearoa, we experienced a dip below one over the summer, but with Omicron beginning to spread the number has climbed to 1.5 and is projected to go higher.
After spreading through our community, the number will drop when the virus starts to hit enough immunity roadblocks - either from vaccinated people or those that survive the virus, Geoghegan says.
If the reproduction number levels out around one for a sustained period, Aotearoa will be in a position to consider treating Covid-19 as endemic.
It will then possibly fill a space similar to the influenza virus, Geoghegan says, where it will constantly circulate at low levels in our society with spikes during winter.
But this scenario depends on how the Covid-19 virus evolves.
If it evolves into a new strain, the reproduction number will spike again.
The capacity of our health system
Another important factor in transitioning out of the pandemic will be if our medical system can handle the levels of infection.
New Zealand will only be able to transition to treating Covid-19 as an endemic illness if our hospital system can cope under the additional strain of having the virus circulating in our society.
The country has not had its hospital capacity tested yet by this pandemic due to our previous elimination strategy.
Pre-omicron, the average global mortality rate of Covid-19 was around 1 in 100 people infected.
Kurt Krause, a virologist and physician at the University of Otago says New Zealand’s health system could not have coped with this.
“[With widespread transmission], one percent is so high it overwhelms the hospital system,” Krause says.
“It would have decimated parts of the population. Especially if you were older or Māaori and Pasifika, whose risk of death was much higher.”
Research found Māori and Pasifika people in their fifties were as likely to be hospitalised by Covid-19 as an 80-year-old Pākehā person. The research highlighted systemic racism and bias issues as the cause, including housing inequity and poorer access to healthcare.
New Zealand is currently several hundred ICU beds short, and lacking adequate supply of some medical equipment.
“The big risk is transmission. If we have too many people that have to go to the hospital, then we have a big problem.”
The mortality rate of Omicron is closer to the flu (0.04) at about 0.09 percent of cases.
This will be manageable for our health system as long as Omicron infections come in waves -, and not tsunamis, Krause says.
“The proof will be in the pudding. We can estimate, but we won't know the tax on the system until it happens. Which is why it is good to move with deliberate speed [in opening up], but not undue haste.”
A cultural shift
An important factor in New Zealand deciding to transition Covid-19 into an endemic illness, is if there is cultural acceptance.
In other words, will New Zealanders accept Covid-19 circulating in our community, and to what extent?
Krause highlights how we already have different approaches and levels of acceptance to endemic illnesses.
“Take for example rabies. If there was an outbreak of rabies, there would be no tolerance for that,” he says.
“But with the common cold, everyone accepts it will happen every year, and they will likely get it every year.”
Geoghegan says we would have to find as a country what our level of tolerance would be for Covid-19 in the community, and what measures we are prepared to undertake in order to achieve that.
“Being an endemic virus doesn’t mean we have to accept large scale outbreaks. That is wrong to assume that endemic means acceptance.”
Aotearoa has shown strong support for Covid-19 health measures. 92 percent of New Zealanders agreed with our initial elimination response in 2020, and 96 percent of eligible New Zealanders have been fully vaccinated.
However, there is also a growing fringe of discontentment. Across May to September of last year, a Government survey showed an increase in opposition to Covid measures - from 12 percent to 16 percent.
According to protestors at the February Convoy protest, this discontentment is primarily around vaccines mandates.
Polling in November, 2021 showed 74 percent of New Zealanders agreed with vaccine mandates in workforces, 20 percent opposed, and 6 percent were not sure.
“I understand that people want to open the borders and ease restrictions, but it is easy to forget that freedom comes at dozens of deaths a day,” Geoghegan says.
“[I don’t believe] we are ready to accept that here.”
The global pandemic
Dr Harriette Carr, deputy Director of Public Health at the Ministry of Health, says it is the World Health Organization (WHO) “which will have the responsibility for declaring the COVID-19 pandemic over”.
As such, the pandemic in New Zealand will not be over until it is over for the whole world.
“It’s important to remember that NZ’s Covid-19 risk is mainly determined by what’s happening in other countries,” Amanda Kvalsvig says.
“If the rest of the world brings Covid under control we’ll be safe too and New Zealanders abroad can travel back whenever they need to.”
Making sure every country in the world has access to vaccines is the key to bringing Covid-19 under control internationally and “shutting down the mutation factory that’s hard at work at the moment”, Kvalsvig says.
A statement from WHO says to end the Covid-19 Pandemic in 2022, the world needs to reach 70 percent vaccination by the middle of the year.
As of February 8, 2022, the world is roughly 50 percent vaccinated.
Countries Covid-19 vaccinations by percentage of population, February 8 2021. Credit: World Health Organisation.
As you’ll see in the map above, lower-income countries are struggling to vaccinate their populations.
“Narrow nationalism and vaccine hoarding by some countries have undermined equity, and created the ideal conditions for the emergence of the Omicron variant,” WHO says.
“And the longer inequity continues, the higher the risks of this virus evolving in ways we can’t prevent or predict.If we end inequity, we end the pandemic.”
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