Covid-19: Rod Jackson - was New Zealand's response to the pandemic proportionate?

Deserted international departures retail stores at Auckland International Airport during the Covid-19 Level 3 lockdown. Photo / Brett Phibbs, File

Opinion

OPINION

In a recent article (Weekend Herald, April 16) John Roughan wrote that the pandemic has been an anticlimax.

Surprisingly, he acknowledges Covid-19 has killed about 25 million people worldwide, so hopefully he was referring to New Zealand's 600 deaths. He goes on to ask how many lives we in New Zealand have saved and states that it's "not the 80,000 based on modelling from the Imperial College London that panicked governments everywhere in March 2020".

I beg to differ. It is because governments panicked everywhere that the number of deaths so far is "only" about 25 million.

A recent comprehensive assessment of the Covid-19 infection fatality proportion – the proportion of people infected with Covid-19 who die from the infection – found that in April 2020, before most governments had "panicked", the infection fatality proportion was 1.5 per cent or more in numerous high-income countries. Included were Japan, Belgium, Denmark, Germany, Greece, Italy, Portugal, Spain, Switzerland and the UK.

Without stringent public health measures, Covid-19 is likely to have spread through the entire population, and an infection fatality proportion of 1.5 per cent multiplied by 5 million (New Zealanders) equals 75,000.

That's close to the estimated 80,000 New Zealand lives likely to have been saved because our "panicking" Government, like many others, introduced restrictive public health measures.

What Roughan fails to appreciate is that public health successes are invisible. Unlike deaths, you cannot see people not dying. Without the initial public health measures and then the rapid development and deployment of highly effective vaccines (unconscionably largely to high-income countries) there would have been far more deaths.

Roughan asks "is this a pandemic?" He states that 25 million Covid deaths are only 0.3 per cent of the world's population ("only" 16,000 New Zealand deaths).

Professor Rod Jackson. Photo / Supplied, File

How many deaths make a pandemic? In 2020, Covid-19 was the number one killer in the UK, responsible for causing about one in 10 deaths in every age group, with each person who died losing on average about 10 years of life expectancy.

In the US, more than 150,000 children have lost a primary or secondary caregiver to Covid-19.

So, has our pandemic response been proportionate?

Stringent public health measures were highly effective pre-Omicron, but are unsustainable long term.

We are incredibly fortunate that highly effective vaccines were developed so rapidly.

Even the less severe Omicron variant is a major killer of unvaccinated people, as demonstrated in Hong Kong, where the equivalent of 6000 New Zealanders have been killed by Omicron in the past couple of months, due to low vaccination rates.

Unfortunately, despite our high vaccination rates, we are unlikely to be out of the woods, and it is likely a new Covid-19 variant will be back to bite us. The only certainty is that the next variant will need to be even more contagious to overtake Omicron.

As long as Covid-19 passes to a new host before killing you, there is no selection advantage to a less fatal variant. We are just lucky that Omicron was less virulent than Delta.

Pandemics over the centuries have often taken several generations to change from being mass killers to causing the equivalent of a common cold.

What response will we accept as proportionate to shorten this process with Covid-19 without millions of additional deaths?

As immunity from vaccination or infection wanes, we will need updated vaccines to prevent regular major disruptions to society.

Unlike the flu, which has a natural R-value of less than two (one person on average infects fewer than two others), Omicron appears to have an R-value of at least 10. That means in the time it takes flu to go from infecting one person to two, to four, to eight people, Omicron (without a proportionate response) could go from infecting one to 10 to 100 to 1000 people.

There is no way that endemic Covid will be as manageable as endemic flu.

The only sustainable proportionate response to Covid-19 is for New Zealanders to embrace universal vaccination.

It is likely that vaccine passes will be required again if we want to live more normally and for society to thrive. It cannot be difficult to make the use of vaccine passes more seamless.

Almost every financial transaction today is electronic and it must be possible to link transactions to valid vaccine passes when required.

Almost 1 million eligible New Zealanders haven't had their third vaccine dose, yet few are anti-vaccination. Rather, thanks to vaccination and other public health measures, the pandemic has been an anticlimax for many New Zealanders and the third dose has not been a priority.

As already demonstrated, for the vast majority of New Zealanders, a vaccine pass is sufficient to make vaccination a priority.

• Professor Rod Jackson is an epidemiologist with the University of Auckland.