The three Rs of Russell & Burch and the testing of biological products.

The principles of humane animal experimentation proposed by Russell & Burch (1959), namely, replacement, reduction, and refinement, are now commonly known as the Three Rs. These principles are clearly embodied in Article 7 of Directive 86/609/EEC. It is instructive, therefore, to consider the priority currently attached to compliance with these principles and to the Directive in the development and control of biological products. Specific comments are made on the need for the application of the Three Rs in relation to the testing of human diphtheria and tetanus vaccines, human pertussis vaccine, inactivated veterinary Gumboro vaccine, veterinary Newcastle disease vaccine, veterinary clostridial vaccines and botulinum toxin. We pose three questions: a. Are the minimum numbers of animals already being used in this area? b. Is any unnecessary pain, suffering, distress or lasting harm being inflicted on the animals used? and c. What could and should be done about any shortcomings in current practice? Finally, the role of ECVAM in the promotion of the Three Rs within the European Union will be reviewed.