In-vivo models or animal-based evaluation of any new chemical/ natural
entity is a necessary stage of the drug development process. To validate the realistic
efficacy of an in-vitro lead for clinical use, pre-clinical animal models are widely used
and also form regulatory requirements in the licensing process, as in-vitro experiments
only provide a potential extracellular drug concentration. However, thorough
investigations using in-vivo models give more details regarding free as well as unbound
drug concentrations present in interstitial fluid. Translation of already approved drugs
for new and emerging viral diseases through repurposing can be a time-reducing, costeffective, and sustainable process as compared to finding a new drug. Considering the
complex interaction of infective agents with the host immune and neuroendocrine
system, the selection of an appropriate animal model is crucial for getting the pertinent,
and precise translatable data. For drugs that have already been approved by the FDA,
in-vivo drug dose and exposure period along with pharmacokinetics data, are generally
known for a disease. This an be utilized to assess a drug's potential usefulness in
treating novel viral indications. Despite of this, anti-infective animal models are
primarily limited to the screening of anti-viral monotherapy and are not substantially
employed for combinational chemotherapies. Here, this chapter summarizes the
different animal and in-vivo models that are in use for screening as well as the
repurposing of drugs for their anti-viral efficacy against numerous emerging and reemerging fatal viral diseases.
Furthermore, the chapter will also provide information regarding the pros and cons of
different in-use in-vivo models for various viral infections, including diseases of global
public health concern.
Keywords: Animal model, Antiviral, Drug repurposing, Viral diseases, Vaccines.
