We all know people who have never had the flu, despite their lack of precautions against the cold, and others who have it every year. Why such an injustice? The answer seems to come ... genes!

The results of a very large-scale study on the subject (published in the American journal PLoS Genetics a few weeks ago) have indeed led to this conclusion.

In this study, the researchers inoculated 17 non-sick volunteers with a strain of seasonal H3 / N2 flu.

Results of the experiment: 9 people became ill while the 8 others suffered absolutely no symptoms.

To better understand and explain these different immune responses, 16 samples were taken from each patient during the 132 hours of the test. After analysis of these, the researchers were able to obtain a "detailed map of the immune response of infected patients", as stated by Nicolas Dobigeon, co-author of the study.

Overall, the various scientific data treatments then revealed the fact that the genes are at the origin of the reaction (or absence thereof) of the immune system when it comes into contact with the influenza virus. explains why Mrs. X is never sick while Mrs. Z reacts systematically to the illness.

This discovery is significant for the medical world since it would develop therapies to prevent the flu. Indeed, people could take precautions before the acute symptoms of the flu are felt, the "inflammatory genomic signature that differentiates the healthy group from the sick group" being measurable until about 36 hours before their onset.