Induction of trained immunity by influenza vaccine: impact on COVID-19

Cross-protective effects of certain vaccines against heterologous infections have been reported, and long-term boosting of innate immunity (also termed trained immunity) has been proposed as the underlying mechanism. Several epidemiological studies suggested cross-protection between influenza vaccination and COVID-19 during the current pandemic. Influenza vaccine responses included significant transcriptional reprogramming of monocytes, while systemic inflammation was reduced. These epidemiological and immunological data argue for a potential beneficial effect of influenza vaccination against COVID-19.EGA study EGAS00001005446