'Tis the month of sniffles, sneezes and snot.
If you're fed up of catching colds then you'll certainly want to take note of a new health study from Yale University, which suggests that the common cold virus reproduces more efficiently in the cooler temperature found inside the nose.
The finding not only proves that people are more likely to catch a cold in cool-weather conditions, but it also shows that wearing a scarf around your face could be the key to tackling illness this winter.
Existing research suggests that the most frequent cause of a cold, the rhinovirus, replicates more in the slightly cooler environment found in the nasal cavity, as opposed to the warmer lungs.
To explore this further, Yale researchers examined the cells taken from the airways of mice. They compared the immune response to rhinovirus when cells were incubated at 37 degrees Celsius, or core body temperature, and at a cooler 33 degrees Celsius.
The focus of the study was on how body temperature influenced the immune system rather than how temperature influenced the virus.
“We found that the innate immune response to the rhinovirus is impaired at the lower body temperature compared to the core body temperature,” said study author and Yale professor of immunobiology, Akiko Iwasaki.
Researchers observed replication of the virus in airway cells from mice with genetic deficiencies - particularly in the immune system sensors that detect a virus and in the antiviral response.
They found that with these immune deficiencies, the virus was able to replicate at the higher temperature. “That proves it’s not just virus intrinsic, but it’s the host’s response, that’s the major contributor,” Iwasaki explained.
“In general, the lower the temperature, it seems the lower the innate immune response to viruses,” noted Iwasaki.
This proves that research may give credence to the old wives’ tale that people should keep warm, and even cover their noses, to avoid catching colds.
Yale researchers also hope to apply this insight into how temperature affects immune response to other conditions, such as childhood asthma.
The study was published in the Proceedings of the National Academy of Sciences.