Why are we asking this question now?
To the horror of farmers and animals, foot-and-mouth disease (FMD) has come back to Britain, just six years after the last outbreak laid waste to the rural economy, costing the country an estimated £8.5bn in lost exports and the impact on tourism.
Its return has revived the argument over how best to combat a disease that is virtually harmless to humans, but hugely infectious among cattle and pigs.
Hopes are growing that the new outbreak will be confined to the Surrey farm where it was identified on Friday.
Were further cases to be discovered, however, the Government's preferred strategy would be to attempt to control the spread through mass slaughter of animals.
But there are large numbers of critics who favour inoculation as a more reliable way of ensuring the disease is eradicated from the country.
Debby Reynolds, the chief veterinary officer, disclosed that 300,000 doses of vaccine had been ordered as part of the Government's "existing contingency plan" for an FMD outbreak. But she stressed that no decision had yet be taken.
The National Farmers Union (NFU), traditionally hostile to vaccination, has acknowledged that it might have to play a part in tackling the disease this time.
What lessons were learned from the 2001 epidemic?
When FMD struck in 2001, the first outbreak for 34 years, the Ministry of Agriculture banned animal movements, imposing strict restrictions on public access to the countryside and ordering the cull of 2.4 million cows, pigs and sheep. It resolutely set its face against vaccination.
The Anderson inquiry into the crisis highlighted gaps in the Government's response although it recognised ministers were facing an unprecedented situation.
It concluded that the country needed a new "national strategy" to help contain animal health outbreaks. It said emergency vaccination should be "an option available" in future, although it ruled out emergency vaccination of healthy animals.
The Northumberland report into the 1967 outbreak, during which 442,000 animals were culled, had reached the same conclusion, backing the future use of "ring-vaccination" (inoculating all livestock in the area around infected animals).
Do they vaccinate in other countries?
Culling remains the preferred option across the EU for containing FMD, although member states are allowed to vaccinate livestock in the event of an outbreak of the disease.
In 2001, when some cases of the disease appeared to spread from Britain to the Netherlands, the Dutch government gave the go-ahead to the vaccination of some 100,000 animals.
Supporters of immunisation also point to comprehensive vaccination in the mid-1990s in Argentina and Uruguay . After the programmes ended, FMD returned to both countries.
Why the reluctance to vaccinate?
Perhaps because Britain is an island nation, it has instinctively preferred to slaughter out the disease, with the NFU leading powerful voices arguing against vaccination of livestock.
They maintain that vaccination is both expensive and time-consuming as it needs to be repeated each six months and is required for each new generation of animals. They also say there are doubts that vaccination is completely effective.
In addition, the export of British beef would be banned for six months. When it was allowed to resume, the industry worries that resorting to vaccination would have sent out a damaging deterrent message to would-be importers of British meat.
The World Organisation for Animal Health places countries into three groups: those where FMD is present (including most of the developing world, where the disease is endemic), those free of the disease through vaccination and those free of it without immunisation. Britain is in the final category and therefore has access to the most lucrative export markets. The scale of the business was underlined yesterday by the Meat and Livestock Commission which calculated that the export ban prompted by the outbreak will cost the red meat industry around £10m per week.
Does vaccination have practical problems?
It has had since the early days of vaccination, when scientists inadvertently caused outbreaks by using dead samples of FMD to inoculate livestock.
There can be a delay to correctly distinguish between the variations of the disease: the 01 BFS67 strain discovered in Surrey is different from the form that swept across Britain six years ago.
Although free of the disease, a vaccinated animal cannot be moved for a time because it can still be a carrier of the infection.
Farmers struggling to survive might not be able to afford the relevant vaccine.
What do supporters of vaccination say?
They counter that biotechnology is fast advancing and animals (as well as humans) are routinely vaccinated against other diseases.
They argue that everyone, apart from vegans, eats meat and dairy products from vaccinated livestock and that culling millions of healthy animals is a huge waste of a valuable resource. The Food Standards Agency has confirmed that eating animals that have been vaccinated is safe.
Above all, they insist that the difficulties of vaccination would be far outweighed by a repeat of the devastating images of funeral pyres of dead animals being flashed around the world for the second time in six years.
Peter Melchett, policy director of the Soil Association, said: "The nature of the countryside has changed. Its economy depends on tourists and visitors ... with farming contributing, in terms of jobs, very little."
There is a final question for Ministers to ponder: Given the widespread distress six years ago over the mass slaughter of uninfected creatures, how would the public react to a repeat of the grisly spectacle?
Where do vaccines come from?
Ironically from the Pirbright research laboratory that has been blamed for the outbreak on Woolfords Farm, Elstead, four miles away.
Merial, the American-based pharmaceuticals company which runs the site and strongly denies being responsible for the crisis, had been producing vaccines for export to South America and Turkey.
Asked how much Merial would be paid for producing the vaccine, Ms Reynolds said: "I cannot give you the financial implications of that. Merial is the supplier of the UK vaccine bank."
Should mass vaccination be used to control foot and mouth disease?
* Mass slaughter, with millions of animals burnt on funeral pyres, would have a devastating impact on rural tourism
* There are no human health risks from eating food from vaccinated livestock
* There would be widespread public revulsion at the spectacle of the slaughter of healthy animals
* International trade would be hard hit, costing farmers millions of pounds in lost exports
* It would be time consuming - animals would need to be inoculated every six months
* It would be a massive logistical exercise and it is not clear who would bear the costReuse content