Emergence dynamics of Sarbecovirus coronaviruses : Zoonose mecanisms. – EmerCoV

The 21st century began with a wave of emerging epidemic infectious diseases, of which COVID-19 is considered one of the most serious, with a devastating impact worldwide. Seventeen years after the emergence of SARS-CoV from 2002-2003, in 2019, it is again a Betacoronavirus Sarbecovirus (SARS-CoV2, the COVID-19 coronavirus) which emerged in humans in similar circumstances than those of 2002. Four years later, more than 774 million confirmed cases and more than 7 million deaths have been reported worldwide (data.who.int/dashboards/covid19, 10 march 2024, OMS). This virus is 95 to 96.85% identical, at the nucleotide level, to Sarbecoviruses detected in horseshoe bats. Beyond the biological origin of this virus, the context and mechanisms that favor its emergence are poorly understood. The correlation between global changes affecting ecosystems and the number of viral emergences requires further research into the processes that link them. The EmerCoV project relies on etho-eco-virological monitoring of colonies of Horseshoe bats and other species harboring Sarbecoviruses (European SARS-related-CoV), which are already carried out for 10 years, and propose to continue these long-term such monitoring and to combine them with experimental approaches in cellular and animal models to dissect virus-host interactions (with a focus on molecular barriers that the virus needs to overcome, such as viral entry and innate immunity). These etho-eco-virological data will be integrated with socio-historical dimensions in a holistic inter-disciplinary approach, where the impact of global changes (modification of ecosystems) on host behavior, viral evolution and the probability of crossing the species barrier will be calculated according to the parameters measured by mathematical modeling approaches combining in particular SIR models and mixed models, to propose informed models for anticipating emergences. Our project will thus provide a better understanding of bat-borne coronavirus emergence in a changing world.