Recent Developments in Alternatives to Animal Testing

At least 115 million animals are thought to be used for scientific purposes every year, worldwide (Taylor et al., 2008). Animals are typically used to test whether an intervention will cause harm to humans or other animals of the same or different species, i.e. safety testing; or whether it will work, i.e. efficacy test­ ing. Interventions can include testing substances (such as cosmetic products, industrial chemicals, drugs, pesticides, food additives, and biocides ); medical devices; surgical techniques; environmental changes; or other ways of altering the physiology and/or behavior of a live animal. Safety testing is highly regu­ lated and is often done after any efficacy testing, if necessary, to finally check that an intervention is safe for humans and/or other animals to use. Efficacy testing is less formalized and often occurs in universities as ideas are tested in live animals as a "proof of concept", often prior to the development of actual interventions to help humans or other animals. Methods that replace techniques that use live animals, or methods of test­ ing substances without live animal use, are known as alternatives, replacements or non-animal methods. Some prefer the term advanced technologies given the fact that they often rely on more sophisticated technology and are more hu­ man-relevant than the animal test they replace (see Langley et al., 2015). There have been efforts to replace animal tests since the 1960s. Significant progress initially came in replacing animals used to diagnose human disease; to produce biological drugs ( such as vaccines); and to safety test batches of these drugs as they were produced. Concerns about safety were the initial driver for this, as drugs produced using animal material could be contaminated with animal diseases. However, cost, efficiency, and the need for swifter and more accurate predictions also played a part. Some of the earliest replacements are, in fact, no longer referred to as such, as they are now standard practice. For example, the