Without extensive testing it's hard to know how deadly a new virus really is. The science resorts to "modelling", extrapolations of limited data using guesswork. In March, researchers at Imperial College London had predicted 500,000 Britons and 2.2 million Americans would die if nothing was done. As the Economist noted recently, these are 10 times the numbers who have died of Covid-19 since then.
Back then governments had not been doing nothing, they'd been quarantining travelers from infected countries, ramping up testing and preparing hospitals for a pandemic. The Imperial College modellers cautioned their numbers were unrealistic, a worst-case scenario. But their model was applied by epidemiologists elsewhere, including Otago University, Wellington, who told governments their hospitals wouldn't cope.
Within days many governments were emulating the US. All around the world doors were slammed shut to all tourism and non-essential travel, followed by national lockdowns. It felt exactly as a British foreign secretary famously described the outbreak of World War I: "The lamps are going out all over Europe. We shall not see them lit again in our lifetime."
Will we see the world lit up for travel again in our lifetime? With the advent of a vaccine it seems now possible. But I greatly fear New Zealand will be the last country to reopen its doors. That fear is based on the Government's celebrated success at keeping the virus out of this country.
Its measures have received a massive public endorsement. At the October election, Labour won an absolute majority of the vote. The last time this happened was 70 years ago, 1951, at a snap election called to endorse a National government's crackdown on an unruly waterfront union.
Then, as now, news media solidly supported the government's response to the crisis. Then, as now, some people thought the threat exaggerated and the measures excessive but their voices were sidelined. Then, as now, the Opposition party fell into line.
The public has been left very fearful of the virus and very confident it can be kept out of the country. That's why so few are bothering to wear masks, keep a social distance, use the tracer app etc. People are staking everything on keeping the virus out. Both fear and complacency rest on the closed border.
The combination of fear and complacency might make it hard to get New Zealanders vaccinated. Why put the thing, or anything resembling it, into your body, many might think, if you can keep it out of the country? That attitude that could keep us isolated in a vaccinated world.
The Government's attitude to a vaccine's limits could keep the border shut too. The Pfizer BioNTech preparation now being injected into British and North American arms has proven effective against illness for 95 per cent of people thus infected but the companies don't yet know whether it can stop infected people passing the virus on.
That is also the case with the Moderna vaccine, expected to be approved by the USFDA yesterday. It has been found effective against the illness and appears to have slowed the rate of asymptomatic transmission by two thirds, but doesn't stop it.
Even if a vaccine does no more than immunise individuals, it should allow us to open the border in my view. Once an inoculation is available free to everyone who wants it, the response to Covid-19 can become a personal choice. You take the vaccine or the risk.
But I doubt the Government will agree. This may be our big debate next year, as the rest of the world gets back in the air.