In the world of medical research, scientists often rely on a special kind of “helper” to tackle complex diseases—animal models. These models aren’t chosen at random; they are carefully selected and, in many cases, genetically engineered to mimic the human body’s systems and disease symptoms. By studying these animals, researchers can explore the causes and progression of diseases, test potential treatments, and evaluate the safety of new drugs long before they reach human trials.
You might wonder: why not just test directly on humans? The answer is as ethical as it is practical. Before any new treatment reaches a clinical trial, it must first be proven safe and effective in animals. This is a critical step to avoid exposing people to harmful or ineffective therapies. In other words, animal models serve as a vital bridge between early-stage research and real-world medicine.
In fact, some of the most significant medical breakthroughs of the last century owe their success to animal studies. Blood transfusions, anesthetics, insulin for diabetes, antidepressants, and even MRI scanners—all of these were made possible thanks to years of research using animal models.
At the NIH’s Intramural Research Program (IRP), researchers work within an AAALAC-accredited animal care and research program. This ensures not only that animals are treated humanely but also that the scientific findings are robust and reliable. The IRP has access to a wide range of sophisticated models, from germ-free mice to genetically engineered non-human primates, and even the world’s largest zebrafish facility.
These resources have played a key role in advancing research into addiction (including opioids, alcohol, and cocaine), developing new cancer therapies, creating an FDA-approved antibody for RSV in infants, and uncovering the genetic causes of various rare diseases.
One particularly powerful tool researchers are using is CRISPR gene-editing technology. With it, scientists can recreate specific human genetic mutations in animals, allowing them to observe how a disease unfolds and identify potential intervention points. In one IRP study, researchers used CRISPR to engineer a mouse with a rare neurological condition, uncovering a treatment target that may one day help children with the same illness.
To make this a little more real, consider the story of Mary Thompson, a retired schoolteacher from Iowa. Her infant grandson was diagnosed with a rare metabolic disorder shortly after birth. The disease shows few signs at first but can quickly lead to severe neurological damage. Fortunately, thanks to years of prior research using mouse models, scientists had already developed an enzyme-replacement therapy. Because of this, Mary’s grandson was treated early and is now a thriving, healthy toddler. “Those scientists—and the little mice behind the scenes—saved our family,” Mary says with emotion.
Of course, running such a large and advanced system isn’t without its challenges. That’s why the IRP is investing heavily in improving animal care, expanding researchers’ access to various models, building a new centralized vivarium to replace aging facilities, and launching a CRISPR core lab to help create novel transgenic animals for cutting-edge studies.
All of these efforts stem from a shared belief: that progress in medicine depends on strong, reliable, and innovative research models. The future of healthcare may very well be swimming in a fish tank, curled up in a lab cage, or swinging in a primate enclosure.
Science never stands still. Across all 27 NIH institutes and centers, IRP researchers are working day and night to unlock new medical frontiers. Behind the charts, data, and lab coats lies a deep commitment to human life. Because of their efforts, and the animals quietly working alongside them, there is real hope for better treatments and, in many cases, real cures.
As technology advances, so too will our ability to simulate diseases more accurately and treat them more effectively. Whether it’s cancer, Alzheimer’s, or ultra-rare genetic disorders, the next big leap in medicine may begin with a tiny heartbeat in a lab—one that could change the course of someone’s life forever.