Influenza vaccine recommendations and coverage (2018-2023): a foundation for pandemic preparedness and response

Seasonal influenza causes millions of severe illnesses and deaths globally, especially in vulnerable populations. Influenza vaccines reduce morbidity and mortality, if given to vulnerable populations prior to the peak influenza season. WHO regularly analyzes data on seasonal influenza vaccination provided by Member States and Territories (MST) to monitor the global status of vaccination policies, programmes, and coverage as national seasonal influenza vaccination programmes have been repeatedly documented to provide a platform for pandemic preparedness and response. This manuscript examines global influenza vaccination coverage between 2018 and 2023. We analyzed the recommendations and vaccination coverage data as reported by MST to the WHO-UNICEF Joint Reporting Form on Immunization (JRF) together with income classifications from the World Bank to report on recommendations and vaccination coverage per WHO region and income groups over time. We undertook two linear regressions to understand associations between higher vaccination coverage rates in older adults and independent variables. Globally, MST reporting to JRF increased over time (from 84% to 93%). While reporting of influenza vaccination recommendations by target group has remained steady (from 65% to 64%), reporting of coverage data increased slightly (from 51% to 53%), with variations between WHO regions. Among MST who completed the JRF, recommendations for vaccinating Health and Care Workers (HCWs) (63%) and older adults (62%) remain the most frequent, with median coverage of HCWs higher than that for older adults in four WHO regions. Median coverage for pregnant women increased substantially in WPR. Gross domestic product was the only statistically significant predictor for high coverage in older adults. Since 2018, a growing number of MST have issued national recommendations for seasonal vaccination and improved coverage of seasonal influenza vaccination, although significant differences remain between WHO regions. Continuing this positive trajectory will keep strengthening national preparedness for and resilience to future respiratory pathogen pandemics.