Leading article: The herd mentality

The new outbreak of foot-and-mouth at a farm in Surrey should be a warning against the dangers of official and political complacency. The indications are that the virus is the same strain that infected herds in the county last month. A new movement ban is in place around the farm in Egham. And the European Union has again imposed a ban on UK meat and livestock exports.

The outbreak is rather puzzling because it is more than 30 days since the last confirmed outbreak, and the incubation period for the disease is two to 14 days. Yet the virus can survive in water for up to 50 days and in hay and straw for up to 20 weeks. So it is possible that the virus survived the initial quarantine. Another possibility is that biosecurity at the Institute for Animal Health in Pirbright has once again been breached. But whatever the explanation, it means more pain for farmers. This is a time of year when livestock farmers would be moving their animals to market. Now that is on hold as the Government's vets attempt to isolate the outbreak.

The reappearance of the disease raises some uncomfortable political questions. Was the Government too hasty in declaring the all-clear last month? It certainly seems so. And the issue of biosecurity is again pertinent. The Government escaped censure when security failings at Pirbright were revealed last week. It is only right that biosecurity levels at the facility should now receive proper public scrutiny.

The new outbreak raises a broader question of policy too. A government-commissioned report by the Royal Society on the disastrous 2001 outbreak recommended that in future healthy livestock on neighbouring premises should be vaccinated as "a major tool of first resort" to prevent the disease spreading further. And the Environment Secretary, Hilary Benn, said yesterday that immunisation is now being considered. But why was vaccination not used, as the Royal Society recommended, when the outbreak occurred in August? Much was made of the Government successfully "learning the lessons" of 2001. But as with the calling of the all-clear last month, that verdict seems to have been premature.

There is a strong counter argument to vaccination of course. If used routinely, it could result in the disease becoming endemic, which would rob British agriculture of its status as "free of foot-and-mouth". This would prevent British farmers exporting to important markets abroad. But is the present situation – recurrent threats to the livelihoods of farmers, culled herds and impeded access to the countryside – really more attractive? It will not take too many more outbreaks to make vaccination look like the only responsible emergency response to foot-and-mouth.