Clinical testing on humans can only begin after a pre-clinical phase, involving laboratory studies (in vitro) and tests on animals, which has shown that the experimental drug is considered safe and effective. However, no animal is sufficiently similar to humans (even genetically modified ones) to make human testing unnecessary. For this reason, the experimental drug must also be tested on humans.
Whilst a certain amount of testing can be carried out by means of computer modelling and by isolating cells and tissue, it becomes necessary at some point in time to test the drug on a living creature. Animal testing is an obligatory stage in the process of obtaining regulatory approval for new drugs and medicines, and hence a legal requirement (EU Directive 2001/83/EC relating to Medicinal Products for Human Use). This applies to prescription and vaccine drugs but not to most over the counter drugs, off the shelf medicines and healthcare products (as the ingredients in them have usually already been tested). The necessity of carrying out prior testing on animals is also stated in the World Medical Association’s “Ethical Principles for Medical Research Involving Human Subjects.
In order to protect the well-being of research animals, researchers are guided by three principles which are called the 3Rs:
1. Reduce the number of animals used to a minimum
2. Refine the way that experiments are carried out so that the effect on the animal is minimised and animal welfare is improved
3. Replace animal experiments with alternative (non-animal) techniques wherever possible.
In addition, most countries will have official regulatory bodies which control animal research.