Since the start of the pandemic, it is commonly accepted that the virus is transmitted, on the one hand by postilions (coughing, sneezing, laughter…), and on the other hand by contaminated surfaces (credit card terminal, handles of carries, objects…). To guard against the first mode of transmission, the wearing a mask has been widespread indoors, and even outdoors, during peak virus spreads.
To protect against the second mode of contamination, the use of gel hydroalcoholic or regular hand washing throughout the day were strongly recommended. Indeed, from the start of the pandemic, analyzes showed that the virus could remain intact on surfaces for 28 days! However, according to a recent study published in the journal ACS Central Scienceit would seem that this mode of transmission is not sufficient to cause infection in humans.
Mucin, a protective protein
The explanation would come from a protein present in our postilions and called mucin. Our mucous membranes produce mucin. Its function is to keep the mucous membranes moist, a bit like a lubricant. It also has the role of protecting our organism from the agents pathogens. By attaching itself to it, it prevents them from entering our cells. In the case of coronavirus, mucin has the property of attaching itself to the Spike protein. When this is masked, the virus can no longer enter the cells.
Non-contaminating contaminated surfaces
When an infected person sputters, the droplets therefore contain virus surrounded by mucin. When these settle on surfaces, the water evaporates within minutes and the bond between the virus particles and the mucins is even stronger. That’s why the sputters suspended in theair still well hydrated are much more contagious than sputter deposited on surfaces for some time and dehydrated.
Why did previous studies on the contaminating power of SARS-CoV-2 deposited on surfaces not lead to this result? Because they have often studied the survival of the virus alone, without taking into account its environment in the postilions.
This discovery could also bring new elements to a very mysterious aspect of the virus: why some people have a severe form of the disease while others are asymptomatic ? The quality of the mucins present in our mucous membranes depends on our state of health and our diet. People with good quality mucins may be better able to block the virus from entering the body, while those with lower quality mucins may be unable to do so, letting in greater amounts of virus. viruses in the body.
Interested in what you just read?