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MANY parts of Britain are closed to visitors. The tourist industry is 
losing
millions every week. The general election may be postponed. And over a
million perfectly healthy cattle, sheep and pigs are being slaughtered in 
a
desperate bid to end the epidemic of foot and mouth disease.

As the carcasses pile up, some experts are questioning the no-vaccination
policy of most developed countries. The relentless rise in international
trade and tourism means preventing such outbreaks is getting harder and
harder, while new vaccines and tests mean there's no reason why countries
that vaccinate shouldn't export, they say. The policy may now be more an
excuse to bar cheap meat imports than it is sound science.

The Netherlands already plans to use emergency vaccination if its outbreak
gets out of control. This means inoculating all animals within 3 
kilometres
of an outbreak and then slaughtering them later. There are hints that
Britain might follow suit.

But Belgium and the Netherlands want to go much further. They are asking 
the
European Union to let them use vaccines routinely. Most EU countries say 
no.
The big problem with vaccination is that some vaccinated animals only 
become
weakly immune. This means they can still be infected and possibly pass the
disease to other animals yet not show any obvious symptoms. This is why
disease-free countries won't buy animals, meat, embryos or semen from
countries that vaccinate.

Stopping vaccination, in contrast, makes it easy to tell if animals are
disease-free, as any stray pathogen will trigger full-blown disease. "If 
you
don't stop vaccinating, you never know if your animals are infected," says
Jim Pearson, head of the scientific department at the OIE, the world
organisation for animal health in Paris.

Gareth Davies, former chief epidemiologist at Britain's ministry of
agriculture, was one of the architects of the EU decision to abandon FMD
vaccination in 1991. At the time, the vaccines were part of the problem.
Standard vaccines are made from killed virus. But not all the viruses were
being destroyed, so vaccines were actually causing most of Europe's
outbreaks, while infection came from elsewhere only occasionally. The same
was true for classical swine fever. "On the whole," says Davies, "the
benefits of non-vaccination outweighed the costs."

Global travel may be moving the goalposts, though. "Now anyone can fly in
from anywhere carrying infected material," says Davies. The EU is the
biggest single destination for international travellers, with arrivals
growing by 4 per cent a year. Travel to the US grew by 19 per cent between
1998 and 2000. And all it takes to start an epidemic is a carelessly
discarded sandwich containing meat from an infected animal.

Accidental introduction isn't the only threat. Brazil blames sabotage for 
an
FMD outbreak last year. And the US is so worried about bioterrorist 
attacks
on its livestock industry it has just spent $40 million on upgrading its
secure research facilities for animal disease on Plum Island, New York.

Davies now thinks vaccination is worth considering again-but only as an
emergency measure. The Netherlands plans to do this because it believes
vaccination would have eased the nightmare of its 1998 swine fever 
outbreak.
However, the country will only regain FMD-free status several months after
it slaughters vaccinated animals.

Then it can sell meat to FMD-free North America and Japan again. Meat from
vaccinated animals is unacceptable there because of the risk of 
sub-clinical
infection-because officially, you can't tell vaccinated and infected 
animals
apart.

Except you can. The current FMD vaccine consists of dead viruses. Animals
given this vaccine make antibodies to the virus's protein coat, but will
never be exposed to the other viral proteins made when the virus infects a
cell. In 1999, the European Commission's scientific committee on animal
health concluded that tests for non-coat proteins would distinguish
vaccinated from infected animals 90 per cent of the time.

Other researchers have even developed specific "marker vaccines" designed 
to
make this task easier. For example, Rob Moormann of the Dutch Institute 
for
Animal Science and Health in Lelystad has created a marker vaccine for
classical swine fever.

An accuracy of 90 per cent cannot guarantee that each animal tested is
clear. But the European Commission has said that it is good enough to
declare a herd uninfected-if 90 per cent of animals are clear, then the 
rest
probably don't have the disease. Despite this, the Commission decided
against using either vaccine.

This makes Moormann angry. "Look at the cost of these recent outbreaks. It
would be better to do routine prophylactic vaccination, then good
surveillance for infection." He says slaughterhouses could routinely test
for these infections along with BSE. Such tests should soon get a lot
quicker and cheaper. The US military is already developing "biochips" to
detect biological weapons, for example.

Routine testing for 20 diseases on one chip could bridge the gap in
veterinary surveillance that let Britain's FMD outbreak spread for weeks
before it was spotted. More to the point, says Moormann, farmers could
vaccinate their livestock and still pick up any stray infection. "It would
cost a lot less to speed the development of this technology than to pay 
for
more big outbreaks."

The EU Court of Auditors agrees. In a scathing review last year of swine
fever management, it wrote: "The Community's non-vaccination policy . . . 
is
called into question by the development of marker vaccines, and the very
high costs associated with the 1997-8 epidemic. The Commission should 
update
its cost-benefit analysis."

Mirjam Nielen, an animal health economist at Wageningen University in the
Netherlands, is doubtful, though. "You would have to pay a lot for
surveillance, and you would have to convince your trade partners you 
really
are disease-free," she says. Convincing disease-free countries such as the
US to accept imports from countries that vaccinate livestock won't be 
easy.

And there is also one big, unspoken benefit of not vaccinating. Under its
current policy, says Nielen, "the EU can keep out imports from a lot of
countries. That probably keeps out lots of odd diseases". It also means EU
producers face less competition.

Over 78 per cent of the EU's meat is sold internally. If the EU started
vaccinating against diseases such as swine fever and FMD, it could no 
longer
refuse to import meat from Russia, much of Africa and South America. That
might explain why the EU is at such pains to hang on to its disease-free
status although the main benefit, at least officially, is that the EU can
export meat products to North America and Japan. Yet even in 1999, before
beef exports were banned, only 5 per cent of the EU's sales were to these
countries.

"Countries will only go back to vaccinating if the costs of not 
vaccinating
look really enormous," says Nielen. Many farmers and businesses in Britain
think the costs are already too high.