COVID-19 hitches a ride on mucus to spread deep into lungs, live imaging shows.

Investigators observed that the movement of mucus can spread the COVID-19 virus inside the respiratory tract, where it later forms aerosols that infect other people.

COVID virus evolves more rapidly in the CNS

New viral variants created in the brain & other parts of the nervous system could also travel back to the lungs, where they could become transmissible. That could spread new, dangerous variants of the virus.