The next two to three weeks will be critical. If, within that time, the outbreak of foot-and-mouth disease in Surrey has been contained, we may be able to breathe again. But the unknowns are still too great for complacency. Roe deer can spread the virus; any movements of farm animals before the disease was detected could be fatal; no one has yet discovered how the organisms responsible for the outbreak escaped. Until we know more, the chances that more animals in nearby areas will have been infected remain high.

One thing, however, has changed, and changed for the better since the 2001 epidemic. Few experts are arguing any longer that the mass slaughter of healthy animals is the only way of containing the disease. That may sound now like a statement of the obvious. But back in the dark days of that insane period six years ago, when funeral pyres lit up the night air across the farmland of Britain, footpaths were barred, and the countryside was virtually closed down to the public, the scientific and farming establishment closed ranks against any suggestion that there might be a more humane approach.

In the name of preserving British exports and the marketing of farm products, seven million animals, most of which were found to be free of the disease, were killed, many of them in harrowing conditions, to the horror of those farmers and vets who were forced to become involved.

I have lost count of the number of high-ranking members of the food industry, the farmers’ unions, and senior scientists to whom I spoke during that time who brushed aside, some with contempt, the notion that vaccination might be a viable alternative. I remember asking the Government’s chief scientist, Sir David King, to explain to me why it was not being considered. “I would need five hours to explain the science to you,” he said. “Unfortunately I don’t have that time.”

Let us not go back there, however. The fact is that there has been, since then, a sea change in attitudes within the Department for the Environment, Food and Rural Affairs (Defra). As recently as the past few months vaccination has been accepted, not just as a contingency plan, but as a prime weapon in the battle to contain the disease. The key argument against its use – that once our sheep and cattle become vaccinated we can no longer claim that British animals are free of the disease – has been quietly shelved. It was always illogical.

Other places, such as South America, where FMD has long been endemic, use vaccination routinely, and still export their meat, much of it to British supermarkets. We routinely eat food from vaccinated animals; so does half the world.

More important, perhaps, was the realisation that the agenda of the food industry and a meat export trade which accounts for less than 1 per cent of our exports should never again take precedence over the wider needs of rural Britain. The evidence of those who witnessed at first hand the emotional distress and economic havoc wrought by mass slaughter in places such as Dumfriesshire and Cumbria, distilled in several clinically argued reports in the aftermath of the epidemic, has been a powerful engine for change. So, too, has the realisation that the science on which so many of those decisions in 2001 were based was less sound than we were told.

It was stated then that there were no tests to distinguish between a vaccinated animal and one that had contracted the disease.

Therefore, it was argued, vaccination would simply mask the full extent of the epidemic, and carriers of the disease would be allowed to spread the virus unchecked. That argument was repeated dutifully by ministers, while those experienced microbiologists with hands-on experience of the disease across the world, who argued against it, were ignored. Again, there is no point in going back into that debate. What is important now is to record how far science has advanced in the meantime.

There are accepted tests that can distinguish between infected and vaccinated animals. They are quick and easy to carry out, and they mean that, if an epidemic takes hold, then only diseased animals have to be killed. We know, too, that FMD “carriers” do not infect other animals – the disease is passed on only by animals or humans who have been in contact with it in its active form.

Among other advances are the so-called “farm-gate” or “pen-side” tests which allow a vet to carry out on-the-spot checks to determine whether a herd of cattle or a flock of sheep has been infected, rather than having to send samples back to a laboratory.

Rapid diagnosis of this kind means that biosecurity measures can be imposed immediately rather having to wait for the results of tests.

Quicker diagnosis means not only a swifter response, but the ability to manufacture and deploy the right kind of vaccine within a matter of days. If an outbreak looks like spreading across a region, then vaccination can begin within that area as soon as it is available, to create a cordon sanitaire around it. Instead of lorries laden with corpses rumbling down country roads, or burning furnaces spreading their noxious fumes through the air, animals can be protected against contracting the disease, and allowed to survive.

I cannot, hand on heart, say that the battle for the vaccine has been won. There are still those in Defra and elsewhere who will argue for slaughter as the only effective response to this disease. But the case for a humane, civilised and scientifically sound policy has strengthened over the past few years to the point where it is beginning to look unassailable. And the most powerful argument of all to be made in its favour is this: I doubt if any of us could stomach a repeat of the nightmare of 2001.

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