Are pregnant women less at risk of developing a serious form of the flu? In any case, this is what the results of a study carried out by researchers at McGill University (Canada), published in the journal ScienceAdvances, suggest.
In mice, pregnancy strengthens an immune defense that prevents the influenza A virus from replicating and in particular from spreading to the lungs, where it can cause a serious infection. “A mother must stay healthy to protect her developing baby, so the immune system adapts to strengthen its defenses. This fascinating response in the nasal cavity is the body’s way of adding an extra layer of protection, which is activated during pregnancy,” emphasizes Dr. Maziar Divangahi, co-senior author of the study, professor at the Faculty of Medicine and health sciences at McGill.
Protection in the nose and upper passages
Concretely, in the mouse model, a certain type of immune cell is activated in the nasal cavity to produce a molecule, interleukin 17, known in particular for its central role in innate immunity. This protein strengthens the body’s antiviral defenses, particularly in the nose and upper respiratory tract. “The influenza A virus remains one of the deadliest threats to humanity,” said first author Julia Chronopoulos. “This natural immunity during pregnancy could change the way we think about flu protection for pregnant women.”
However, in France, as in Canada, where the study was carried out, it is recommended that pregnant women be vaccinated against the flu. They are considered at risk of developing a serious form of the disease. “Pregnancy indeed leads to a change in immunity, it increases the risk of bacterial infection with the possible occurrence of pulmonary and cardiac complications,” writes Ameli.fr. Pregnant women would also be more likely to have a long shape. And a high fever could also be dangerous for the good progress of the pregnancy.
-Treatments inspired by this natural barrier?
According to the study authors, their discovery paves the way for more targeted influenza vaccines. It could also benefit the entire population. “The general population could also benefit, because our results suggest that the immune response we observed could be reproduced beyond pregnancy,” said co-senior author Dr. James Martin, professor at the Faculty of Medicine. Medicine and Health Sciences at McGill. The idea? produce vaccines or treatments that increase nasal production of interleukin 17.
Please note: each year in France, the flu epidemic is on average responsible for 20,000 hospitalizations and 9,000 deaths.
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