A team of scientists from the University of North Carolina (USA) has published a new snapshot of the process of how SARS-CoV-2 invades the lungs. This virus, 100 nanometers – 10,000 times less than a millimeter – attaches itself to hair-shaped extensions known as cilia, which are found in some cells that line the respiratory system.

In an article published this week in New England Journal of Medicine have made new analyzes that show what is the distribution and density of the SARS-CoV-2 when it is infecting the lungs. Their results confirm the great potential of virions – viral particles – to infect the lungs.

Image of coronavirus on cilia.
UNC School of Medicine

The research consisted of inoculating the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into human bronchial epithelial cells, which are found in the bronchi and act as barrier between blood and bloodstream.

This inoculation, which was performed in a biosafety level 3 facility, had a multiplicity of infection. Specifically, they detected three million plaque-forming units for each culture dish. In the image provided by the researchers, the viruses (in pink) can be seen on the respiratory cilia (blue) along with some mucus (green).