Scientists from Texas Biomed and Southwest National Primate Research Center (SNPRC) published their findings on a comprehensive animal model study of SARS-CoV-2 in the journal Nature Microbiology. These findings were initially published online on BioRxiv in June 2020. The study evaluated three non-human primate (NHP) species (Indian rhesus monkeys, African baboons, and common marmosets of New World origin) to determine the susceptibility to SARS-CoV-2 and the development of COVID-19 disease . During the research process, macaques and baboons have shown great promise as animal models for COVID-19 disease research. Based on the results, the researchers suggested using rhesus monkeys as a model to develop vaccines, while baboons showed greater disease development trends, making them a potential option for evaluating antiviral therapies and comorbidities, such as understanding the link between COVID-19 and Diabetes or COVID-19 and heart disease. "The advantage of Texas Biomed's unique research model is that its expertise can support personal scientific research and contract research with animal, biosafety, and regulatory capabilities on a campus, thereby helping from basic discovery to preclinical development to human clinical Extensive research on the trial.” explains Dr. Joanne Turner, vice president of research at Texas Biomed.
Animal models for infectious diseases (such as COVID-19) enable scientists around the world to determine whether candidate vaccines and antiviral therapeutics currently under development can be used as human interventions. In addition, animal models enable scientists to understand the disease progression of people with compromised immune systems to assist in the development of treatments for these people. Dr. Deepak Kaushal, Director of the Southwestern National Primate Research Center, said: “Finding an animal model suitable for COVID-19 can make these key discoveries immediately. This is an important step in the fight against this disease. If there is no detailed animal data, the FDA will not It is very likely that vaccines or antiviral therapies can be used in humans, even in animals currently undergoing human trials, because animal model data can ensure that we have a complete understanding of this disease and human response. Potential treatments."
A team of 43 researchers reported the clinical, viral, imaging, immunological, and histopathological (tissue examination) findings during the SARS-CoV-2 infection/COVID-19 disease in these three NHPs. The study finally found that non-human primates showed similar progression of SARS-CoV-2 infection to humans. Some infected people were more sick than others, and there were signs of virus and pneumonia in the upper and lower respiratory tracts.
Dr. Kaushal explained: "Our results tell us that as we learn more about diseases, therapies used in human trials and vaccine targets, these animal models will provide relevant and quantifiable information."
Although previous animal studies have shown that macaques are a viable model of SARS-CoV-2, this is the first time that researchers have conducted longitudinal studies on three different primate models. In addition, the researchers used the most comprehensive assessment method, from bronchoalveolar lavage (lung fluid collection) and nasal swabs to determine the presence of the virus, and then to chest X-rays and CT scans to assess lung health after infection.
The results show that the macaque and baboon models will form strong signs of acute viral infection, leading to pneumonia. This study found that the immune system of non-human primates reacted strongly and cleared the infection. Special bone marrow cells flow from the blood to the lungs and secrete high levels of type I interferons, cytokines, etc. The appearance of these special phagocytes corresponds to the decline of virus and disease indicators.
This study is also the first report that SARS-CoV-2 infection specifically changes lung lymphoid cells (T cells). A strong and very specific immune response is generated in macaques, allowing animals to clear the virus. This finding indicates that the primate model will help understand the immune response to SARS-CoV-2, help formulate interventions that can produce a similar response, and help assess the safety of vaccines that require special treatment And effectiveness. To produce an immune response.