This publication provides a detailed analysis of the extent to which experiments on primates have been replaced by advanced non-animal alternatives. The report includes five case studies that demonstrate the need and potential for replacing non-human primates in medical research.

Following are estimates of the numbers of primates used in research, drug development, and safety testing:

• European Union: 10,451 primates used in 2005
• United States: 62,315 primates used in 2006
• Japan: 2,802 primates used in 2004
• Great Britain: 3,125 primates used in 2007

In 2005, the official European Union (EU) opinion survey found that 82% of EU citizens believe that we have a duty “to protect the rights of animals, whatever the cost.”

Malaria research offers a strong possibility of replacement of some or all primate models, which have been used in research for the past three decades. However, despite this research, primate models have often resulted in inadequate outcomes that may not have resulted in improved human health.

Primates share many psychological attributes with humans, and consequently are used to research memory, cognition, learning, and social communication. However, over the last few decades, human imaging and related technologies have emerged as new approaches to understand the human brain more than any other method. Greater investment in imaging technologies could further enhance the scientific advantages of human imaging over invasive primate studies.

In stroke research, scientists believe that the phylogenetic similarity of non-human primates to humans makes them the animals of choice for assessments of behavior and cognition. However, it is this similarity that makes this use of primates unethical. In addition, differences in pathophysiology between primates and humans are likely to be reflected in the outcome of an experimental procedure. Potential alternatives to this type of research include functional magnetic resonance imaging (fMRI), quantitative structure-activity relationships (QSAR), human microdosing, proteomics and genomics, in vitro stroke studies, and post-mortem studies.

In AIDS and vaccine research, there are important differences between humans and non-human primates. Primates can be infected with HIV, but they do not develop AIDS. Multiple experimental vaccines have been found to prevent infection in monkeys, but have been ineffective in humans. Repeated failure of animal-based research illustrates the lack of causation to subject primates to invasive, lengthy, and terminal AIDS experiments. Alternatives include population studies, clinical research (in vivo and ex vivo), tissue, cell, and molecular research, and mathematical modeling and statistical analysis.

The use of non-human primates in Hepatitis C research includes repeated blood sample collection, and liver resections. However, mathematical modeling allows the possibility of replacing chimpanzees with pharmacokinetic modeling, which uses computer simulations to predict the absorption, distribution, metabolism, and excretion of substances such as novel drugs. In addition, in vitro human models are also being devised and implemented in the field.