In 1959, William Russell and Rex Burch introduced the concept of the “3 R’s”—the replacement, reduction and refinement of animal use—in an effort to advance animal welfare standards and reduce animal use in science.
When Russell and Burch developed this concept, they prioritized the 3 R’s in a hierarchy, with replacement as the ultimate goal, followed by reduction and then refinement. Refinement was to be considered only when “[r]eplacement is not (yet) possible, and every device of theory and practice to reduce the number of animals to a minimum has been employed.”
Given that, in many ways, the world of biomedical sciences is very different now compared to when the 3 R’s were first established—especially considering the advancements that have been made in the development of human-relevant, non-animal in vitro and in silico models—it is fitting to evaluate how today’s scientists view the 3 R’s.
A recent article in PLOS One reported on the results of a survey that was designed to assess researchers’ awareness and application of the 3 R’s in addition to their approach to ethical issues in animal experimentation. The survey was conducted in Europe before and after the researchers took a laboratory animal science course designed to teach them about the 3 R’s and raise standards of animal welfare.
Even though the 3 R’s have steadily gained acceptance over the last half of a century and are incorporated into legislation regarding the use of animals in science, the survey’s results revealed that only 52.9% of respondents were able to name the 3 R’s prior to the lab animal course. Following completion of the course, 92.9% of respondents were able to name them, indicating that the course had successfully raised awareness about the replacement, reduction and refinement of animal use.
The survey also asked scientists to prioritize the 3 R’s. Although Russell and Burch intended for replacement to be the highest priority followed by reduction and then refinement, researchers prioritized the 3 R’s in the reverse order, regarding refinement as the top priority. We’ve reported on this concerning trend previously.
Prioritizing the 3 R’s in this way highlights potential deficits in laboratory animal courses to sufficiently inform researchers about the importance of replacement and the significance of non-animal methods. These courses must do a better job of highlighting that even if we refine methods to make them more humane and reduce the number of animals used in experimentation, we are still relying on animals to model human biology—and this is a problem.
We know that human-relevant models do a better job of accurately reflecting human biology, and that they therefore give us the best chance of improving human health and well-being. By encouraging the increased availability and validation of reliable non-animal alternatives, we can help “flip the script,” and shift the prioritization among researchers from refinement and reduction to replacement.
Help NAVS fund the development of these human-relevant in vitro and in silico models that can replace animal use, so that the 3 R’s can be implemented in the manner in which they were intended.