A global review of seasonal influenza vaccine introduction: analysis of the WHO/UNICEF Joint Reporting Form

<b>Background</b>: Influenza is a highly contagious disease that affects the upper and lower respiratory tract caused by several subtypes of influenza viruses. While vaccination remains the mainstay strategy to protect populations against influenza, there is a global shortage and inequitable access to influenza vaccines. Although influenza vaccine production capacity increased from 500 million doses in 2006 to 1.5 billion doses in 2013, little is known about the global distribution of these vaccines albeit its introduction. We assessed the global status of influenza vaccine introduction. <b>Research design and methods</b>: We analyzed data from the World Health Organization (WHO) Joint Reporting Form, a publicly available source of immunization data from 194 countries of all six WHO regions. We used 2017 data, available as of July 2018. <b>Results</b>: By December 2017, 117 of 194 (60%) WHO Member States had introduced the seasonal influenza vaccine. European and American regions accounted for 70% (82/117) of the total number of countries that had introduced influenza vaccine. The other four regions account for only 30%. Ninety-four percent (50/53) of countries in the European region and 91% (32/35) in the American region had introduced influenza vaccine. In the Eastern Mediterranean and Western Pacific regions, 67% (14/21) and 52% (14/27), respectively, had introduced the vaccine. Yet only 27% (3/11) and 9% (4/47) in the Southeast Asian and African regions, respectively, had introduced the vaccine. Among countries (<i>n</i> = 117) that had introduced the vaccine, children (56%), older adults (87%), and risk groups (99%) were prioritized and given the vaccines. <b>Conclusions</b>: Introduction of influenza vaccine in the African and Southeast Asian regions remains suboptimal. This critically underscores the need for financing mechanisms and having countries in the regions that are lagging behind to prioritize seasonal influenza vaccine.