This blog post examines the limitations of animal testing, focusing on the Thalidomide incident, and explores the necessity of human trials and alternative technologies.

The Thalidomide Incident and the Limits of Animal Testing

Thalidomide, a drug developed in 1957, was intended to prevent morning sickness in pregnant women. After undergoing clinical trials on mice, it began selling with advertising claims hailing it as an unprecedentedly safe miracle pill. However, tragedy soon struck: over 10,000 babies with severe birth defects, known as ‘Thalidomide Babies,’ were born across 46 countries worldwide. Subsequent experiments on dogs, chickens, cats, and hamsters showed no toxic reactions, yet it was ultimately revealed that this drug caused fatal harm only to humans.

Definition and Spread of Animal Testing

This case clearly demonstrates the limitations of animal testing. Animal testing refers to experiments or scientific procedures conducted on laboratory animals for scientific purposes such as education, testing, research, and the production of biological agents. Animal testing is deeply embedded in our daily lives and is widely used, particularly to determine whether chemicals in cosmetics we use daily are harmful to humans. However, such animal testing for human safety sometimes degenerates into a tool for scientists’ curiosity and pleasure, raising questions about whether animal testing alone can fully detect substances harmful to humans.

Additional Examples of Animal Testing Limitations

Beyond the thalidomide incident, numerous other cases demonstrate the limitations of animal testing. For instance, the medical community knew as early as the 1960s that smoking causes lung cancer, yet animal testing over the next 50 years failed to clearly establish the correlation between smoking and lung cancer. Consequently, the dangers of smoking remained unknown to the public for a long time, during which many people died from lung cancer. Another example: As early as the early 1940s, clinical trials on humans revealed that asbestos causes cancer. However, all subsequent animal experiments failed to prove the link between asbestos and cancer, delaying warnings about asbestos’ dangers for decades. Furthermore, polio research conducted on monkeys provided incorrect information about polio, leading to the implementation of flawed preventive measures.

Counterexample: Tylenol and Aspirin

There are also counterexamples. There are drugs that cause adrenal insufficiency in cats with just one dose, leading to fatal outcomes. There are also drugs that cause congenital malformations in rats and severe blood pressure abnormalities in cats at just 20% of the human single-dose amount. Who would readily take such drugs? Yet surprisingly, the former is ‘Tylenol’ and the latter is ‘aspirin’.

The Necessity and Benefits of Human Testing

Such cases demonstrate that current animal testing alone cannot accurately predict situations that may arise when administered to humans. It is possible that a substance deemed harmful to animals and discarded in the laboratory might actually hold the potential to cure incurable human diseases. For this reason, human experimentation emerges as an indispensable element.
The necessity of human experimentation can be demonstrated in several ways. First, because humans and animals are not identical, human trials yield far more accurate and reliable information than animal testing. For instance, only 1.16% of diseases are shared between humans and animals. Consequently, a substance that passes animal testing may prove harmful to humans, while conversely, a substance beneficial to humans may be harmful to animals and thus fail to show efficacy.
Second, the history of medicine demonstrates that major discoveries were made through human experimentation. Significant medical breakthroughs in fields like heart disease, cancer, immunology, anesthesia, and psychiatry were achieved through observing patients and dissecting human cadavers. Without such human experimentation, the medical technology we enjoy today would be unimaginable.
Third, human experimentation can contribute to economic revitalization. In human experiments, subjects must be compensated, typically in monetary form. This compensation provides opportunities for economically disadvantaged individuals to participate in economic activities, thereby increasing the circulation of money. Furthermore, this money can empower them to develop their capabilities and seize opportunities for success.

Ethical Considerations and Technological Advancements in Human Experimentation

The paramount principle in conducting human experiments is the utmost respect for human life. Horrific practices like the Nazi experiments on Jews are utterly unacceptable, and experiments that violate human rights cannot be permitted under any circumstances. Advances in computer technology can minimize adverse effects during the pre-experimental phase. For example, computer simulations can predict how specific molecular structures will function within living organisms. Advanced cell culture techniques have also been developed to infect human cells with disease-causing bacteria or viruses.

The Nuremberg Code and Rule Establishment

For human experimentation to be conducted safely, well-established rules and ethical standards are essential. The Nuremberg Code, created after World War II through reflection and criticism of the horrific experiments conducted by Nazi doctors, provides the foundation for these rules. According to this code, human experiments must be conducted with the voluntary consent of the subjects, who must be provided with sufficient information about the experiment. Furthermore, subjects have the right to withdraw from the experiment at any time during its course.

Changing Perceptions and Conclusion

The establishment and adherence to such rules have improved perceptions regarding the safety and reliability of human experimentation. A 2013 survey conducted by the Center for Information and Support of Clinical Research Participation (CISCRP) in Boston, USA, indicated that safety concerns about human experiments have decreased, and perceptions among participants have shifted positively.
This article presented the necessity of human experimentation to overcome the limitations of animal testing, explaining the reasons under categories such as safety, rationality, and cost-effectiveness. It also proposed minimizing side effects by utilizing technologies like computer simulation in the pre-clinical stages. If rules ensuring the human rights of participants are established, human experimentation will become an essential element for the advancement of human medicine. For these reasons, I support human experimentation.