The World Health Organization (WHO) has recommended the composition of the trivalent influenza vaccine for the southern hemisphere winter 2018 influenza season in a report published 28 September 2017.

On 19-21 February 2018 the World Health Organization (WHO) agreed on the recommended composition of the trivalent influenza vaccine for the northern hemisphere 2018-2019 influenza season.

On 18–20 February 2019, the World Health Organization (WHO) agreed on the recommended composition of the quadrivalent influenza vaccine for the northern hemisphere 2019–2020 influenza season: an A/Brisbane/02/2018 (H1N1)pdm09-like virus, an A(H3N2) virus component to be announced on 21 March 2019, a B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage) and a B/Phuket/3073/2013-like virus (B/Yamagata/16/88 lineage).

On September 2019, WHO has agreed on the recommended composition of the quadrivalent and trivalent influenza vaccines for the southern hemisphere 2020 influenza season.

The United States Advisory Committee on Immunization Practices (ACIP), which advises the Centers for Disease Control and Prevention (CDC) on vaccine issues, voted to approve a new recommendation on  February 24 to offer seasonal influenza vaccination to the whole population aged 6 months and older.

​An important conclusion from this process is that the current situation, with B viruses dominating (80%), is likely to continue through the season.

This initiative was taken following the indication of a potential association between the 2009 pandemic influenza A(H1N1) monvalent vaccine and the occurrence of narcolepsy following reports, especially in children from Finland and Sweden.

This recommendation for the Northern Hemisphere is the same as for the season 2010-2011 and for the Southern Hemisphere season.

In February 2011, ECDC published a report concerning a rise in narcolepsy in children and adolescents in some northern countries.

​The European Parliament adopted a resolution on the evaluation of the pandemic in its sitting on the 8th March 2011.