Cotton rats are known for ruining cotton crops, but they are also a uniquely valuable model for studying human pathogens

Studying human pathogens in rodents can be challenging because most mice and rats aren’t susceptible to the viruses that affect us. Not the cotton rat. When they are exposed to influenza, for instance, the virus enters the cotton rat’s lungs and begins replicating. They get sick, just like us. Which is why the cotton rat would appear to be uniquely valuable to evaluate drugs for some of the world’s toughest communicable diseases.

Yet until recently, cotton rats were not widely used. The rodents, so-named because they damage cotton crops, are difficult to handle, lacked inbreeding and so were not commercially available. The use of cotton rats picked up largely due to the growing threat of global pathogens such as Ebola, chikungunya and Zika viruses, said Charles River Research Scientist Carmen Sweeney.

“Infectious diseases are a major public health concern, claiming over 17 million lives every year,” says Sweeney, Scientific Director of In Vivo/Ex Vivo Testing Services at Charles River’s site in Ballina, Ireland in an interview with the journal International Clinical Trials. “The WHO reports that nearly 50,000 men, women, and children die every day from infectious diseases.”

“The cotton rat model is being used to examine the efficacy and immunogenic properties of (vaccine)candidates,” says Sweeney in an interview with the journal International Clinical Trials. “Preliminary results would indicate that the cotton rat is proving to be an excellent model for these products.”

Sweeney said cotton rats are also important in the evaluation of preventive and therapeutic RSV vaccine and antiviral candidates, and down the road will be valuable in the development and release testing of adenoviral vector-based gene therapy and studying infectious disease pathogenesis. You can find the entire interview with Sweeney here.