Scientists from universities and research centers in the Netherlands and Germany have found that influenza vaccination protects against coronavirus. Vaccination efficiency was 47% in the first wave of the pandemic and 50% in the second. The research results were published on the medRxiv preprint portal.
The publication notes that some vaccines, in particular, the drug for tuberculosis BCG, enhance immunity against other pathogens. This phenomenon is called trained immunity.
At the start of the pandemic, Raudbaud University collaborators with colleagues from other research centers decided to test how effective the annual flu shot against COVID-19 is. To do this, they studied the data of employees of a large Dutch hospital.
It turned out that the incidence among those who got the flu shot was 47% lower – 2.1% of them were infected, and 3.3% of unvaccinated employees. During the second wave, the effectiveness of the influenza vaccine was even higher – 50 percent.
The authors of the publication suggest that this is due to the effect of trained immunity. Scientists studied blood cells of participants before vaccination and after – in those who received the vaccine, changes in the transcription profile of cells responsible for immunity were observed.
Genetic analysis showed that after vaccination against influenza, genes were expressed in cells that help protect against coronavirus. Changes were found in the regulation of 136 genes. The maximum effect of enhancing immunity was observed six weeks after vaccination.
The researchers noted that the results of their study correlate in many ways with earlier studies that showed a link between the flu shot and the milder course of the coronavirus.