A mouse could save your life

If you are confused about the rights and wrongs of animal experiments, you can be forgiven. Protests on the streets of Oxford for and against the university's new scientific research centre have done little to dispel the smog of propaganda that has descended over the animal debate.

We have been told testing on animals reveals nothing about people. We hear about alternative research that is just as good if not better than animal experiments. We learn about the children who have suffered because scientists and drug companies are obsessed with the irrelevant results of experiments on animals.

Yet few realise that Britain has one of the toughest laws in the world governing animal experiments. Animals can only be used when scientifically justified - their use in cosmetics testing was stopped in 1997 in Britain. Scientists and their research institutes also have a legal obligation to use alternatives to animals whenever possible. If they can use alternatives, not only is it incumbent on them to do so, but it can be cheaper.

There are fewer animal experiments now than 20 or 30 years ago mainly because of developments in techniques that can replace the use of living animals. Scientists can sometimes carry out a test on people rather than laboratory animals, or they can try to "model" a living system or medical problem using powerful computer software. But, as the cosmologist Stephen Hawking once said: "Computers can do amazing things. But even the most powerful computers can't replace animal experiments in medical research."

Organisations opposed to animal experiments take the opposite view. They say that not only do alternatives to animals exist, but they are better. They also claim that relying on the results of animal research is dangerous. "Reliance on animal experimentation amounts to gambling with our children's' health," says the antivivisection group Europeans for Medical Progress (EMP). "Time and time again, misleading results from animal experimentation have proved tragic or fatal when applied to children and babies. And there are much better options."

The thought that animal experiments directly harm people, that they are next to useless for medical progress and that their only outcome is unnecessary suffering is surprising, if not alarming. But what evidence is there to back up such claims?

This was the question posed last year by the Advertising Standards Authority (ASA) when it was investigating a complaint against EMP (then called Europeans for Medical Advancement). For instance, the ASA was interested in the evidence to support this claim by the group: "Treatment of childhood leukaemia has also improved dramatically, thanks entirely to ingenious research on cell and tissue cultures - not to animal experiments."

Or this statement: "The biggest obstacle in the search for cures for cancer and many other diseases of childhood is our irrational dependence on animal experimentation, which has cost far too many thousands of lives." EMP also claimed the leukaemia drug Glivec had been discovered entirely through test-tube research not involving animals.

When the ASA challenged the group to support these claims, EMP cited research dating back to the 1940s and 1950s. Understandably, the ASA ruled that people reading the group's literature are hardly likely to consider 50 or 60-year-old research as recent improvements. The ASA also found that Glivec, a recent treatment for chronic myeloid leukaemia, was developed with the help of animal research.

But opinion masquerading as fact seems to be a hallmark of the animal debate. EMP has stated, for instance, that "uncritical reliance on the results of animal tests can be dangerously misleading and has cost the health and lives of tens of thousands of humans".

This opinion on the subject of toxicity testing lies at the heart of the argument against the use of animals in medical research. All drugs in use today have been tested on animals before being given to people. The aim is to ensure as far as possible that side-effects are kept to a minimum and that potential toxicity is detected before a new drug goes on the market.

Of course there are drugs that have slipped through the safety net. They may have not shown any adverse effects on animals, or even on the patients who took part in the early clinical trials, but after some months or years the side-effects of long-term use become apparent. Anti-vivisectionists exploit the inevitable risk of missing potentially toxic drugs using animal testing.

One of their favourite examples is the case of Thalidomide, a morning-sickness drug which was tested on animals without any apparent side effects before being found to cause limb deformities in the unborn babies of pregnant women. Thalidomide is frequently cited as a drug that was deemed safe in animal tests, illustrating the anti-vivisectionist mantra that testing on animals tells us about animals, not about people.

In fact the animal tests on Thalidomide failed because they were not as extensive as they should have been. After the drug was withdrawn, scientists went back and tested the drug on rats, but this time the researchers included pregnant animals - astonishingly pregnant animals were not included in the original experimental protocol. The results were unequivocal: Thalidomide caused spontaneous limb deformities in foetuses. It was a finding that would almost certainly have resulted in the drug being banned - had the fact been known - long before it was prescribed to pregnant women.

Using animals to test the toxicity of new drugs stops as much as 80 per cent of putative treatments from ever getting near to being given to patients. As a screen against the side-effects of new drugs, animal experiments are not perfect but without them there would be many more dead or damaged people.

Another shibboleth of the anti-vivisectionist movement is the belief that animal experiments have provided little, if any, insight into basic science or medicine. Yet according to an extensive investigation in 2002 into animal experiments by the House of Lords, all reputable scientific and medical organisations in every country of the world say that animal research has been crucial in the understanding of health and disease. The Department of Health's submission to the Lords' inquiry was clear about the critical role played by animal experiments. "Research on animals has contributed to almost every medical advance of the last century," it said. "The NHS would be unable to function effectively were it not for the availability of medicines and treatments that have been developed or validated through research using animals."

So where exactly do we stand regarding the known facts about animal research? It is widely accepted that Britain has one of the toughest sets of regulations governing animal experiments anywhere in the world. Indeed, many scientists claim that the bureaucracy involved in getting a Home Office licence or amending it is so convoluted that it can take anywhere between six months and a year - as opposed to weeks in other countries.

In 2004, the last year for which we have full figures, there were 3,550 licensed projects in Britain and just over 2.85 million "procedures" on animals, which can include relatively benign operations such as taking a blood sample. The number of procedures has increased slightly in recent years due to the use of genetically modified mice in studies to understand the human genome. Genetically altered animals were used in just over 914,000 regulated procedures in 2004 - about a third of all procedures. About 67 per cent of all licensed experiments were carried out on mice and 16 per cent on rats. Other mammals accounted for four per cent.

No scientists derives enjoyment from inflicting suffering on animals, and many researchers are working on alternatives. However these alternatives are not yet at a stage to rival the complexity of the whole living organism.

Until alternatives do reach that stage, animal research will still be needed if society is to enjoy the benefits of science and medicine.

Steve Connor is the Science Editor of 'The Independent'

What would we do without animal experiments?

* Polio: Research into polio vaccines required the living nerve-tissue of animals to ensure that the virus used for vaccines causes the paralysis typical of polio. No cultures of human or animal tissue work as well. The inherent dangers of the live vaccine means that it also has to be tested on animals. GM mice have replaced monkeys.

* Kidney disease: Some 5,000 people develop kidney failure each week in the UK and a third would die without a transplant or regular dialysis. Experiments on animals led directly to the development of dialysis machines and to the drugs and techniques for successfully transplanting organs without rejection.

* Cystic fibrosis: Modern genetics research is revolutionising the understanding of inherited diseases, and much of the work can be done without using animals. But, having identified six compounds that could block the defective cystic fibrosis gene using non-animal experiments, scientists had to use lab mice to find the most active drug.

* Tuberculosis: TB infects some two billion people in the world, killing three million people each year. Mice with impaired immune systems are central to attempts to make a viable vaccine against the bacterial disease. All antibiotics used to treat patients have been tested on animals.

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