This text is taken from our newsletter “Coronavirus mail” of May 30, 2022. To subscribe, click here.
Flu vaccines have a “surprising” property. A dose of these inactivated viruses would help prevent the risks associated with COVID-19.
This is confirmed by a Qatari study reported in the journal Nature. The odds of developing a severe form of COVID-19 had dropped by 90% in a population of 30,000 healthcare workers vaccinated against the flu before the pandemic, the researchers said.
The study published in early May has not yet been peer-reviewed, but “it may be true,” confirms Denis Leclerc, researcher in vaccinology at Laval University.
While the result is “surprising,” he says, the underlying mechanism is less so. The flu vaccine “puts the person in an antiviral mode,” explains Mr. Leclerc. “A good vaccine will generate a good immune response. […] It lights up a lot of receivers [des barrières face aux infections]. »
This defensive mode activated by the influenza vaccine does not last very long, however, according to the Qatari researchers, between six months and two years at most. The patients studied contracted COVID-19 an average of six months after their flu shot.
Other cases of this type of cross-protection exist in the vaccine world. The tuberculosis vaccine, for example, is used to prevent bladder cancer. “It’s a form of immunotherapy, if you will,” adds Denis Leclerc.
His team is working on a drug designed to boost a person’s overall immunity. “We talk more about resistance than fighting” the virus.
This roundabout way of preventing disease could save thousands of lives if a new virus hits the planet. “It might have helped at the start of the pandemic,” notes Denis Leclerc. “As soon as there is a focus of infection, we can treat the people around by stimulating the immune response. »