Khaberni - Half of the people exposed to cold viruses actually feel sick, but a faster immune response in the nose can stop colds early, according to a new study at Yale University.
On the other hand, cold air, pollution, and smoke may worsen the symptoms.
In an attempt to explain why some people experience severe symptoms while others do not, the research team investigated what happens inside the nasal passages during colds.
According to Health Day, the researchers found that how the nasal passage cells respond to the rhinovirus, the most common cause of colds, determines whether a person will develop symptoms and how severe they will be.
Dr. Ellen Foxman, senior author of the study and an immunologist at the Yale School of Medicine, said: "This study provides a more detailed picture of what happens during the infection of common colds than we had before."
Some people do not catch colds
Rhinoviruses spread more widely during the winter months, but not everyone exposed to them gets sick.
In fact, about half of the infections lead to symptoms, as Foxman explained.
To understand why, the researchers cultured human nasal tissue in the lab and exposed it to the rhinovirus.
The difference in nasal response
In one case, the response was quick. Less than 1% of the cells were infected because the immune system released interferons, proteins that prevent viruses from entering cells and spreading.
When this response occurred quickly, the virus was stopped before it could cause disease.
However, when the interferons were delayed or disrupted, the virus spread more easily. In these cases, 30% or more of the cells were infected, leading to inflammation and increased mucus secretion, the classic symptoms of a cold, and then people actually felt sick.
