Animal studies have and will continue to serve an essential role in medical development and public and animal health. This stays true for the current global efforts to find treatments and vaccines to combat the COVID-19 pandemic caused by the SARS-CoV-2 virus. Animal studies are not only critical for understanding pathogenesis of COVID-19, but also required to evaluate the safety and efficacy of a drug or vaccine at preventing COVID-19. The importance of animal studies is exemplified by several works recently reported.

One of the most important ways scientists develop and test new therapies for COVID-19 is through experiments with animal models, such as mice. However, SARS-CoV-2 cannot infect mice because of the difference between the human ACE2 receptor and the mouse version. Consequently, researchers have had to genetically engineer mice by adding a human ACE2 gene to mice. In a study published in the journal Cell Host & Microbe on May 26, 2020, the researchers created a new mouse model using a CRISPR/Cas9-based technology that can be used for modeling SARS-CoV-2 infection (Cell Host & Microbe, May 2020). Compared to other genetically engineered mice, this mouse model is genetically more stable, having an expression pattern of human ACE2 receptor better matching that of humans.

In addition to the mouse model, scientists have studied the effects of COVID-19 on other animal models, including macaques and baboons. In a study conducted by the Texas Biomedical Research Institute, the researchers found that macaques rapidly developed clinical signs of viral infection and inflammation but recovered within a two-week period (see Rivard Report). The researchers believe that studying the macaques’ rapid immunological response could be helpful in developing a treatment for patients with COVID-19.

Another important use of animals comes in the development of selective antibodies that can neutralize the SARS-CoV-2 virus. The recent development of “nanobody” therapeutics derived from llamas and camels serves as an exciting new advancement in medical research. Nanobodies are a novel class of very small antibody-like molecules. As a result of their small size and simplicity, they can be manufactured at low cost, have high stability, low immunogenicity, and can be of very high affinity. These factors make nanobodies excellent candidates for therapeutics and diagnostics. It is currently an active research direction to engineer llama nanobodies capable of neutralizing the SARS and MERS viruses to generate nanobodies for neutralizing the SARS-CoV-2 virus.

Because animal studies play an essential role in the development of treatments and vaccines for COVID-19, regulators, along with many researchers and biomedical ethicists, argue that animal studies should not be bypassed, despite the urgency of finding a solution to block the progression of the COVID-19 pandemic. One concern of skipping animal studies is the risk of vaccine enhancement associated with coronavirus vaccines, as expressed by Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases (NIAID): “There are diseases in which you vaccinate someone . . . you actually enhance the infection. You get a good feel for that in animal models . . . . The worst possible thing you can do is vaccinate somebody to prevent the infection and actually make them worse.” (

The significance of the retention of animal studies is also identified in a report recently published by global regulators. “For all SARS-CoV-2 vaccine candidates it is necessary to obtain data in animals and to characterize the immune response induced by a SARS-CoV-2 vaccine candidate.” (See Global regulatory workshop on COVID-19 vaccine development).

Fox Rothschild is endeaving to help our clients as they drive the research and discovery to further understand the SARS-CoV-2 virus and to combat the COVID-19 pandemic. We have a team of experienced attorneys dedicated to assisting our clients in securing their intellectual properties in COVID-19 vaccines and therapeutics ( Additional information about coronavirus resources for businesses, including veterinary practices can be found at:

Joe Chen is a  summer associate at Fox Rothschild LLP