The cotton rat (S. hispidus) is susceptible to non-adapted human RSV and displays many features of human pathology. The cotton rat model, such as that developed at IBT Bioservices in partnership with Noble Life Sciences, has successfully tested RSV vaccine and therapeutic candidates leading to IND and clinical development. Animals are infected by intranasal inoculation with RSV-A2, and readouts may include:
Model kinetics dictate peak viral burden at day 4 or 5 post challenge followed by recovery through day 7. The efficacy of test therapeutics and vaccines is best measured by determining viral load at the peak of infection. Lung viremia is another indicator of morbidity in the cotton rat model.