The Commission does not agree with the petitioners' assertion that animal research is of limited value and argues that animal studies have contributed significantly to improved health and quality of life as well as to longer life expectancy. It adds that  animal tests are still required by Union legislation to authorise human clinical trials, and to protect health and the environment.

The Commission claims that animal models, like all research tools, have their strengths and limitations, depending on the question to be addressed. It replies that “[f]or instance, zebra fish have provided an excellent model to study developmental processes of higher organisms. Mice are a highly informative model for many human genetic diseases, e.g. for hearing, vision or bone disorders - but of limited value for studying Ebola, or acquired immune deficiency syndrome (AIDS), for example.”

“Technological advances have revolutionised biomedical research, bringing new possibilities to improve our knowledge, such as the capacity to sequence the genome of organisms, computational tools to analyse biological processes and to simulate the complex mechanisms involved in health and disease. Innovative tools include human 3D-tissues and reconstituted mini organs. These major breakthroughs allow the development of alternatives based mainly on cell or tissue cultures, as well as computational methods, thus replacing, reducing and refining animal use, where possible.

The Commission considers that the ultimate goal of full replacement of all use of animals for scientific purposes is most efficiently progressed through focused and targeted efforts. The Directive provides for a strategy that is a legally binding step-wise approach as soon as scientifically satisfactory methods become available. The statistical reporting under the Directive was revised in support of this same objective. The new, more comprehensive and detailed data, including on animal suffering, will facilitate the identification of animal use areas on which efforts by the Commission, Member States and other stakeholders for the development and validation of alternative approaches will have the widest impact in progressing towards the ultimate goal.”