Comparative morphological characterisation of SARS-CoV-2 and influenza B virus using atomic force microscopy

Influenza B virus and SARS-CoV-2 virus are the two most representative respiratory infectious diseases. These two viruses not only show similarities in clinical symptoms but also have numerous similarities in microstructure, which is difficult to distinguish and poses great challenges for diagnosis. In this work, the three-dimensional structures and surface features of influenza B virus and SARS-CoV-2 virus were investigated using atomic force microscopy. The results indicated that there were substantial differences in surface morphology and structure between the two viruses. Specifically, the average diameter of SARS-CoV-2 virus particles was around 222.8 nm while that of influenza B virus particles is smaller at about 191.2 nm. The height of SARS-CoV-2 particles was also larger, averaging about 30-60 nm, while that of influenza B virus particles averaged around 10-30 nm. Additionally, the crown-like structure on the surface of the SARS-CoV-2 virus was sparser and more prominent than that of the influenza virus. These findings offer significant insights into the distinction between the two viruses, aiding in the accurate characterisation of SARS-CoV-2 and influenza viruses and facilitating timely and effective treatment strategies.