David Hammond (Letters, March 13) is incorrect to suggest that there are alternatives to animals in research in every case.

Since 1986 it has been illegal to use an animal if an alternative method is available.

Animals are therefore used in medical, veterinary and environmental testing only when there is no alternative. The badger tuberculosis vaccine, for instance, was developed and tested using animals, and can be used in place of a cull, as is currently happening in Wales.

It is also illegal to use an animal to test cosmetics or their ingredients. Furthermore, it is illegal to import animal-tested cosmetics into the UK. But, since we are not going to stop using medicines, if medical research was outlawed in a similar way, it would simply move abroad, where lab animal welfare standards tend to be lower.

The technologies Mr Hammond refers to as “alternatives” to animals, such as cell cultures, computers and human volunteers, are in fact already used and constitute the majority of medical research techniques.

However, without understanding how biological systems work in a living being it is impossible to model them using a computer.

Most research animals are mice or fish, and around half of licensed experiments in the UK each year are related to the breeding of genetically manipulated mice with, for instance, genes turned on or off to discover how they work. There is no virtual way of simulating that process.

Nobody uses an animal if there’s an alternative.

Understanding Animal Research supports greater funding for research into possible alternatives but the debate is not well-served by pretending there are ready alternatives to animals currently in UK labs.

Unfortunate as it is, we cannot immediately move away from using the animals we do without dealing a blow to medical, veterinary and environmental research.

Dr Elisabeth Harley, policy and communications officer, Understanding Animal Research