A study of more than 30,000 healthcare workers in Qatar, the Middle East, found that those who received an influenza vaccine had almost 90% less likely to develop severe covid-19, compared to those who had not recently been vaccinated against the flu. This was reported this week by the journal Nature through its official website.
The investigations, which were carried out in late 2020 before the launch of the covid-19 vaccines, were in line with previous (theoretical) work that suggested that boost the immune system through influenza vaccines could help the body defend itself against SARS-CoV-2.
The scientific team, which was led by Laith Jamal Abu-Raddad, an infectious disease epidemiologist at Weill Cornell Medicine–Qatar in Doha, tracked 518 workers who had tested positive for SARS-CoV-2 and compared them with more than 2,000 study participants. who tested negative for the virus.
“Those who had received a flu shot that season were 30% less likely to test positive for SARS-CoV-2 and 89% less likely to develop severe covid-19”, reads the website.
There is a time limit
Although this is “important evidence,” according to Mihai Netea, an infectious disease specialist at Radboud University Medical Center in Nijmegen, the Netherlands, it is unclear how long this protection lasts.
Among study volunteers, SARS-CoV-2 infections occurred, on average, about six weeks after vaccination. For this reason, “I don’t expect the effect to last long,” says Netea, adding that he calculates that the benefits could last between six months and two years.
The reason why these types of vaccines would work has to do with the fact that, although they train the immune system to recognize a specific pathogen, they also accelerates broad-acting antiviral defenses.