Monkeying around with human health
Using primates damages and kills people
Primates have failed researchers with regard to their ability to predict dangerous side effects of medications. For example:
Hormone replacement therapy - given to millions of women following research in monkeys - has recently been found to increase their risk of heart disease, stroke and breast cancer.
Isoprenaline doses (for asthma) were worked out on animals, but proved too high for humans. Thousands of people died as a result. In subsequent tests, even when the researchers knew what to look for, they were unable to reproduce this effect in monkeys.
Carbenoxalone (a gastric ulcer treatment) caused people to retain water to the point of heart failure. Scientistsretrospectively tested it on monkeys, but could not reproduce this effect.
Flosint (an arthritis drug) was tested on monkeys - they tolerated the medication well. In humans, however, it caused deaths. (6)
Amrinone (for heart failure) was tested on numerous nonhuman primates and released with confidence. People haemorrhaged, as the drug prevented normal blood clotting. This side effect occurred in a startling 20% of patients taking the medication on a long-term basis.
Arthritis drug Opren is known to have killed 61 people. Over 3,500 cases of severe reactions have been documented. Opren was tested on monkeys without problems.
Aspirin causes birth defects in monkeys but not in humans.
'It is the actual results of teratogenicity [birth defect] testing in primates which have been most disappointing. Of the 15 listed putative human teratogens tested in non-human primates, only eight were also teratogenic in one or more of the various species...' - Dr. JL Schardein, author of 'Chemically Induced Birth Defects'.
Despite these failures, marmosets, in particular, are increasingly popular as the 'second species' - in addition to rodents - required by regulators responsible for licensing new drugs. They are attractive to pharmaceutical companies because they are small and easy to breed in captivity. Their size makes them cheaper than dogs to dose with expensive test compounds and easy to house in small cages and inhalation chambers.
These benefits are itemised in a paper published by the Association
of the British Pharmaceutical Industry in 2001.
Stolen from the wild
Not only do monkeys endure the trials of laboratory life, many are imported from such distant countries as Mauritius, Israel, Indonesia, the Philippines and China. 53% of procedures in 2001 involved animals imported from such sources outside the EU. Investigations by the British Union for the Abolition of Vivisection (Paradise Lost available at www.buav.org) and by the RSPCA (Counting the Cost: available at www.rspca.org.uk) reveal appalling conditions at some breeding centres, which are often founded, re-stocked and augmented with animals trapped from the wild. Capture from the wild causes huge distress. The first-generation offspring are sold to UK laboratories, having been taken from their mothers as young as six months old. Their journeys to the UK are in tiny, cramped crates and can last as long as three days - some monkeys have died in transit.
Species under threat
Concern about the use of macaques, in particular, is heightened by their conservation status. Long-tailed (also known as crab-eating or cynomolgus) macaques and rhesus macaques are the most commonly used species. They are 'old world' monkeys, native to Asia, where they live in large social troops that sometimes number 100 individuals. They are very communicative and maintain close relationships through mutual grooming. The long-tailed macaque is listed as near-threatened on the 2000 International Union for the Conservation of Nature 'red list'. The Japanese macaque is listed as endangered; yet up to 2,000 are captured and sold to Japanese laboratories every year. China is the main source of rhesus monkeys for Britain but housing conditions there are particularly horrifying. Breeding stock is taken from wild populations, which are in serious decline.
'Drawing from the wild poses an additional threat to the conservation status and, ultimately, survival, of some species and local populations.' Counting the Cost, report by the RSPCA (see above)
Monkey data is rubber-stamped
UK law states that the use of primates is permissible only if the researchers can demonstrate that no 'lower' species could be used instead. Yet regulators (the Medical Healthcare Products Regulatory Authority in the UK) accept marmoset toxicity data without query. This further encourages their use purely in order to gain easy official approval.
A fundamental point is that the use of primates - or indeed any animal species - for medical research has never been properly scientifically evaluated to see if their use produces benefits for human medicine. This was confirmed when Portsmouth South MP, Mike Hancock - on March 31 2004 - asked an apparently innocuous parliamentary question of the Home Secretary. 'What recent research', Hancock wanted to know, had his Department 'commissioned and evaluated on the efficacy of animal experiments?'
The answer was unequivocal. 'The Home Office has not commissioned or evaluated any formal research on the efficacy of animal experiments.' In the language of tabloid newspapers, this admission was a 'bombshell'. Here was the government department in charge of regulating vivisection admitting that it had - neither recently, nor at any other time - bothered to assess in a systematic way whether experimenting on animals produced beneficial results for people. The starkness of the admission was made all the more glaring by the 'cut and paste' paragraphs that followed it in the formal written answer to Hancock. 'Animal experiments must be judged to be potentially efficacious in order to be licensed under the Animals (Scientific Procedures) Act 1986, which requires that animals may only be used in scientific procedures where such use is fully justified, where the likely benefits outweigh the costs to the animals involved, and where the procedures are most likely to produce satisfactory results.'
The startling inconsistency in this answer is hardly difficult to detect - the Home Office will never grant permission for animals to be experimented upon, it was saying, unless it is sure that such experiments produce benefits that outweigh the harm done to the animals. Yet it has never itself bothered to develop a formal test - based on its own research or anyone else's - by which it can make such a judgement
'Most of the animal tests we accept have never been validated.
They evolved over the past 20 years and the FDA is comfortable with
them.' - Anita O'Connor, Food and Drug Administration (USA)
Better research methods
There are more reliable methods to predict the safety and effectiveness
of drugs for people. These include in vitro (test tube) studies
using human cells and tissues, and sophisticated computer simulations
designed to mimic human metabolism. A ten-year international study
proved that human cell culture tests are more accurate and yield
more useful information about toxic mechanisms than traditional
Screening new drugs in silico (on computer) is now taking the place
of many animal tests. German biotech company 4SC designs new drugs
entirely in silico and can process in one day what would take other
biotechs a month. 'The time is fast approaching when what we are
doing will be the industry norm,' says chief executive, Ulrich Dauer.
'We have the accuracy, the speed and we don't waste time with drugs
that are not going to work.'
The following example illustrates the ineffectiveness of assessing
drug safety in animals and the impossibility of detecting subtle
human responses: Eight out of ten drugs that were withdrawn from
the US market between 1998 and 2001 had serious side effects in
women that had not occurred in men.
If men cannot predict the effects of drugs for women, how on earth can we expect to obtain reliable data from monkeys?
Infectious disease research
Failure of the 'animal model'
Investigating diseases that infect humans in any species other than humans is nonsensical, as pathogens and immune responses to them are highly species specific. For instance, chimpanzees are essentially immune to the human AIDS virus, Hepatitis B and C viruses, the malaria parasite and many other pathogens to which humans are susceptible.
'Up to this very day, all infectious diseases affecting humans are far from having appropriate animal models and, even in those cases where such infections are possible, the symptoms observed in animals and the course of the disease are often very different from those encountered in humans.' - Handbook of Animal Models of Infection, Academic Press, 1999, p.7
The recent anthrax attacks in the US mail were initially not taken seriously enough because experiments on monkeys showed the bacterium was not fatal until 8-10,000 spores are inhaled. When people died from much smaller doses it became apparent that this does not apply to humans.
The same failings apply to vaccine development:
'...prevention [of polio] was long delayed by the erroneous conception of the nature of the human disease based on misleading experimental models of the disease in monkeys.'
Despite mounting evidence of vaccine research failures in animals, tens of thousands of primates and other animals have been killed in AIDS research over the past 20 years. This is despite the fact that infecting animals, even chimpanzees, with HIV does not produce an equivalent disease to human AIDS.
Chimpanzee AIDS research abandoned
This reality has long been recognised by many in the research community and by AIDS activists, who have campaigned hard against futile vaccine research in monkeys.
'What good does it do you to test something [a vaccine] in
a monkey? You find five or six years from now that it works in the
monkey, and then you test it in humans and you realise that humans
behave totally differently from monkeys, so you've wasted five years.'
After an extensive review of the American AIDS research programme,
the US government concluded that chimpanzees are a deficient 'model'
for use in AIDS research and redirected $10 million of funding.
Even the director of the Yerkes Primate Centre admitted that 15
years of AIDS research in chimpanzees had produced little data relevant
Everything we know about HIV and AIDS has been learned from studying people with the disease - through epidemiology and in vitro research on human blood cells. Using primates to predict how humans will respond is not simply unproductive, it has resulted in medical catastrophe. In the early 1980s, the observation that HIV did not affect chimpanzees led scientists to assume that the virus would be harmless to humans too. They consequently advised health authorities to allow transfusions with contaminated blood samples, thereby giving rise to the French blood scandal that claimed thousands of innocent victims.
The first five-year trial of an HIV vaccine, 'Aidsvax', based on
success in animals has recently been pronounced a failure.
Far too frequently, animal models have been used to develop vaccines that are effective in laboratory animals but are ineffective, or actually harmful, in humans. AIDS is a terrible illness, and research money and personnel need to be directed toward methodologies that are viable. Using an archaic methodology like animal models to combat a 21st century disease is more than foolish, it is immoral.
Exercise in futility
Experimenting on monkeys with the hope of unlocking the secrets of the human brain is an exercise in futility. The most dramatic difference between humans and any other species, including the great apes, is found in the central nervous system. Our brain is four times larger than that of a chimpanzee, which is four times larger than that of a macaque. The human brain is enriched with specific cell types implicated in communication, language, comprehension and autonomic functions.
'For cortical regions, such as the language areas, we cannot
use the macaque brain even as a rough guide as it probably lacks
In addition to anatomical differences, the pattern of gene expression
in our brain is dramatically different from that of the chimpanzee.
Many of the attributes that we most celebrate - such as our ability to express ourselves in prose, poetry, song and dance - are uniquely human. We are clearly different, very different, from chimpanzees.
Yet at British universities, including Oxford, Cambridge, Manchester and London, monkeys are still used - at taxpayers' expense - as models of human brain function.
This is despite the fact that human brains can now be studied non-invasively using high-tec scanners. These enable the conscious brain to be observed while engaged in a variety of cognitive tasks (e.g. talking, singing, reading, writing) of which monkeys are not capable - and thus could clearly not provide any relevant insight.
Functional MRI scanners can monitor the brain activity of volunteers undertaking tests of memory and other skills, to reveal brain areas that are active during particular activities. Transcranial magnetic stimulation (TMS) temporarily disrupts brain function, allowing scientists to assess the impact of 'switching off' specific regions without permanently removing them. The Dr Hadwen Trust for Humane Research is funding such studies into epilepsy research at Oxford University. There are many other state-of-the-art imaging techniques now available, including PET (positron emission topography), CAT (computer-aided tomography), MEG (magnetoencephalography), EROS (event-related optical signals) and VBM (voxel-based morphometric analysis). These remarkable techniques are able to differentiate such subtleties as musical ability or whether someone is lying or how hard they are concentrating. Insights that can be gleaned from monkeys seem absurdly crude by comparison.
One recent study of macaque monkeys at Oxford University was aimed
at determining the role of the cerebellum in cognition, by making
a series of lesions in their cerebella.