Why do some people never have colds?

An American study focused on the body's defense process against the cold virus. Researchers have found that the airways struggle to fight two different stressors,colds which some people explains the increased risk of infection.

You've probably noticed in the office this person who seems to be in good shape while the whole team is always sniffing and blowing their noses. She seems immune to microbes, but what is her secret? In fact, airway cells can have different reactions to the same virus. In this case, it is the rhinovirus, one of the main causes of colds, asthma attacks and other respiratory diseases.

According to a new study published by Cell Reports, when this virus enters the nasal passages, cells lining the airway are expected to react before it can multiply and cause cold symptoms. In some people, this defense mechanism works better than others. Yale University researchers have therefore tried to understand why.

Virus and oxidative stress

For their study, they exposed human defensive cells, from the nose or lungs, to the rhinovirus. They found that nasal cells were better equipped to treat the virus. Scientists then observed the antiviral response of cells and their response to oxidative stress. They have noticed that when cells defend themselves against oxidative stress, they are less effective at repelling the virus.

People who are constantly exposed to harmful environmental substances, such as smoke, are therefore more likely to become ill because their first line of defense is engaged in fighting oxidative stress.

"The airways are doing pretty well if they have one stressor at a time, but when there are two different stressors, there is a tradeoff to make," says lead author Ellen. Foxman. "When your airways are trying to cope with another type of stress, they can adapt, but the cost is the risk of rhinovirus infection."