Why do we get sick more in winter? The latest study shows that the problem is in the nose
We know that winter comes hand in hand with an increase in the common cold and other respiratory infections.
This is partly because we spend more time indoors with other people and viruses survive better in drier air. But scientists have now discovered that the immune system inside our nose attacks viral intruders - and that this defense mechanism works best when it's warm.
The researchers say the findings, published in the Journal of Allergy and Clinical Immunology, could help develop future treatments against the common cold and other viral diseases such as COVID-19.
"There's never been a compelling reason why you have this very clear increase in viral infectivity in the cold months," said study co-author Benjamin Bleier, a surgeon at Harvard Medical School.
"This is the first quantitative and biologically plausible explanation that has been developed."