“SO WHAT?” It’s the question doctors across Britain are asking themselves this week, says the GP leading Farnham’s response to Covid-19 Dr Ed Wernick, as NHS England scales up its roll-out of the new coronavirus antibody test.

Until recently, the only coronavirus test available in the UK was the polymerise chain reaction (PCR) test, which looks for specific DNA sequences of the virus and can tell whether you’re currently infected with Covid-19.

But a second antibody test has recently come on to the market, having the potential to tell if a person has already had Covid-19 and is possibly immune to catching the virus again.

This could prove an invaluable weapon in the coronavirus fightback, allowing health workers to treat patients without fear for their own safety, and helping communities and the economy return to normal.

However, concerns remain over the accuracy of the antibody test, with its sale currently on hold to allow for further assessment. And GPs are still in the dark as to what they should do with the results, said Dr Wernick.

The GP said: “The biggest concern for me is the ‘so what?’ question.

“So if you either test positive or negative, what do you then do? And what we don’t have is any guidance.

“Is the advice you don’t need to wear PPE any more? You don’t need to socially distance? You can’t pass it on to anybody else?

“We don’t have that information, so the antibody test doesn’t actually change clinical management at present and won’t unless clinical guidelines are developed to accompany it.”

Dr Wernick cited childhood vaccines which need multiple injections at two, three and four months old, or require a pre-school booster, to achieve and maintain immunity.

“We know that having the virus doesn’t guarantee long-term or lifelong immunity,” he said. “We are learning all the time and it is only time that can give us some of these answers.

“So with the coronavirus, we don’t know what level of antibodies you need for immunity, and the current testing is more binary. It’s yes or no, rather than how many antibodies you have – and if does become quantitative, we don’t know what the therapeutic level is to confirm immunity.

“And then, if you are immune, will that immunity last? Will it last a year, five years, ten years or six months – and do you need another challenge to the immune system to re-prime it? That’s what we don’t know.

“But ultimately, if we get to the point where the information coming back from the test will tell you that you’re going to be immune for the next year and you don’t need to wear PPE, and you can’t pass it on to anybody, then it will be hugely helpful for one’s own personal safety, family members, community and help to restart the economy.

“People will be able to get back to work more quickly and more safely. It would make contact tracing faster as well because you’ll be able to build up a database of who has had the virus, and who can’t pass it on to others.

“That sort of information would be hugely powerful in the fight against Covid-19.”