The new coronavirus test will be useless as long as we lack the capacity to reach the whole UK population

Editorial: It has been one of the symbolic failings of the government’s response to this emergency, and unfortunately remains so now

A reliable antigen test could provide more certainty and lead to better policymaking (Getty)

Immersed as so much of the world has been in the pandemic, having grown used to the “new normal”, it is sometimes easy to forget how sudden and recent the outbreak has been.

A matter of weeks ago, little was understood about the “novel coronavirus”, an early and entirely apt name for it. Now, the first apparently reliable antigen test for having had coronavirus (or not) has been developed by Swiss firm Roche, and approved for use by Public Health England.

Even by the standards of the world’s leading pharma companies, it is a remarkable turnaround. It will be ready for use in a few weeks. After various false alarms about wonder treatments, and the bizarre episode when President Trump suggested that bleach could be checked out as a treatment, it marks the first significant step forwards in the struggle to control Covid-19.

So now, at least in principle, the world will be able to test, albeit still with some margins of error, for those who have coronavirus, and also for those who have had the disease. One of the most difficult aspects in managing the outbreak is the way the disease can spread before the victim shows any symptoms, and how many people can carry the pathogen without showing any symptoms at all. It is this that has made it an especially insidious threat to human health, frightening individuals, forcing lockdowns and wrecking livelihoods.

Now there will be more certainty, for all. Those who have had the virus will know that and draw whatever comfort they can from it. It is still too early to know how much immunity anyone will have derived as a result, or for how long it will last.

The introduction of “immunity certificates” would be premature; but people will be able to make a judgement about their behaviour based on a better level of knowledge. Including those who may have mistaken the flu or hay fever for Covid. Even so, for the sake of the wider population, the authorities will need to ensure that coronavirus “survivors” continue to follow cautious scientific advice. The precautionary principle retains all of its traditional power.

The new test will also mean far better policymaking, based on evidence. For example, Sage will have an understanding of how far any given community is to “herd immunity”. Early surveys, such as the latest one from the Office for National Statistics, indicate that infection rates are nowhere near the levels that would mean herd immunity can be taken into account when assessing the risks in further relaxing lockdown. Yet in due course, the moment will arrive when the post-infection rate reaches, say, 60 per cent of a population. With other factors, that intelligence will make for better decision-making.

In one way, though, Britain remains way behind where it needs to be. For a new test is useless if a country lacks the infrastructure to test its citizens. That has been one of the symbolic failings of the government’s response to this emergency, and it remains the case. As so often in such episodes, the scientists may have overachieved, but the politicians are still underdelivering.