While October 2022 was the hottest month in France since meteorological measurements began in 1945, with a record average temperature of 17.2 degrees, and November quietly follows, oscillating between days of bright sunshine and quick rain to thwart our sartorial predictions, cold and flu season returns, and adds to a Covid-19 that never left.
What is the effect of these infections on our immune system? Do coughs, sore throats and untimely sniffles only make us exhausted, or do they make us more robust in the long term?
From one infection to another
Our immune system has what is commonly called a memory, that is to say that if we have been exposed to an infectious microbe, certain immune cells in our body, which circulate in the blood and bodily fluids, will remember its appearance, and be ready to trigger a rapid immune response if they come into contact with it once more – this is more or less the principle of vaccines, which expose us to small doses of viruses to that our body develops adaptive immunity.
However, catching a cold does not protect us from catching another a few weeks later. As University of Surrey Professor of Immunology Deborah Dunn-Walters explains, “We call it a cold, but there is no single pathogen that is responsible for it: many, many, many. different agents can cause a cold”.
Pablo Murcia, a virologist at the University of Glasgow, points out that “exposure and disease are two different things. We’re exposed to viruses and other pathogens all the time, and often we mount a response without even realizing it’s there. What I…