Electron microscopy overview of SARS-COV2 and its clinical impact

Research centers around the world are competing to develop therapeutic and prophylactic agents to provide new intervention strategies that could halt or even help slow the progression of the COVID19 pandemic. This requires a deep understanding of the biology and cytopathology of the interaction of SARS-CoV-2 with the cell. This review highlights the importance of electron microscopy (EM) in better understanding the morphology, the subcellular morphogenesis, and pathogenesis of SARS-CoV-2, given its nanometric dimensions. The study also underscores the value of cryo-electron microscopy for analyzing the structure of viral protein complex at atomic resolution in its native state and the development of novel antibodies, vaccines, and therapies targeting the trimeric S spike proteins and the viral replication organelles. This review highlighted the emergence in a short period of time of several viral variants of concern with enhanced transmissibility and increased infectivity. This is due to the elevated affinity of the host receptor with acquired adaptive mutations in the spike protein gene of the virus.Subsequently, to the technical improvement of EM resolutions and the recent promising results with SARS-CoV2 variant structure determination, antibodies production, and vaccine development, it is necessary to maximize our investigations regarding the potential occurrence of immune pressure and viral adaptation secondary to repeated infection and vaccination.