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.
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.
In 2022, the first and second most reported zoonoses in humans were campylobacteriosis and salmonellosis, respectively. The number of cases of campylobacteriosis and salmonellosis remained stable in comparison with 2021.
Campylobacteriosis and salmonellosis were the most frequently reported zoonotic diseases in humans in the EU in 2022. For West Nile virus, an increase of the number of infections was observed.
Genetic and antigenic characterization data generated at the Worldwide Influenza Centre for viruses with collection dates after 31 January 2023 until 31 August 2023 informed the WHO influenza vaccine composition meeting (VCM) in September 2023 when recommendations were made for the southern hemisphere (SH) 2024 influenza season.