Wearing a mask helps slow the spread of COVID-19 by preventing the transmission of droplets and aerosols that are produced when a person breathes, speaks, coughs, or sneezes.
Carrying it a little lowered or half, leaving the nose out, is a very bad idea: the nose is the main route of entry for the virus .
Cells of the nose
In April, an international team of researchers determined that the nose is a key entry point for SARS-CoV-2, the virus that causes COVID-19. Their work, which was published in the journal Nature Medicine , explained that nasal cells, in particular, contain high levels of the proteins that SARS-CoV-2 attaches to in order to enter the body. The proteins are called ACE2 and TMPRSS2 .
To trace protein pathways for the virus, the researchers examined donor tissue samples that included cells from the lung, eye, nose, intestine, heart, kidney and liver.
Waradon Sungnak , an immunologist at the Wellcome Sanger Institute and lead author of the study, explained that the researchers examined cells in the nose as an afterthought and did not anticipate that they were all that important.
Since the nose is a main route for the virus, putting on the mask correctly is crucial, fitting it well so that there are no openings on either side so that aerosols do not leak (they behave like smoke).
Another study , published in Cell in July, pointed out the importance of protecting the nose . A team tracked how the coronavirus entered the lungs and where the initial site of infection was.
The researchers mapped surface receptors in the airways to determine which areas contained the most ACE2 proteins . They determined that the highest concentrations of these proteins are found in the nose, rather than in the deep lungs as they had anticipated. After exposing tissue samples to SARS-CoV-2, the team determined that the nose was the most fertile site of infection in the entire respiratory system.