In this report, we present an update of the 2020 primary systematic review, to take into account more recent evidence on the efficacy, effectiveness and safety of newer and/or enhanced seasonal influenza vaccines for the prevention of laboratory-confirmed influenza in individuals aged 18 years and over.
Risks of an adverse event following influenza vaccination are far less common than complications related to influenza itself, and the adverse events are generally localised and mild.
Injected trivalent inactivated influenza vaccines are most commonly used throughout the world. Influenza antigen preparation varies between manufacturers.
Fleas are ectoparasitic blood-sucking insects with the ability to jump, which commonly infest wild and domestic animals (mainly dogs and cats) but also humans.
Several viral and bacterial respiratory pathogens are expected to continue co-circulating at variable levels during the coming months, and contribute to increased morbidity and mortality during this period. This is typical of every winter season.