WHO: Recommended composition of influenza virus vaccines for use in the 2018-2019 northern hemisphere influenza season

22 February 2018
It is recommended that quadrivalent vaccines for use in the 2018-2019 northern hemisphere influenza season contain the following:
an A/Michigan/45/2015 (H1N1)pdm09-like virus;
an A/Singapore/INFIMH-16-0019/2016 (H3N2)-like virus;
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).
It is recommended that the influenza B virus component of trivalent vaccines for use in the 2018-2019 northern hemisphere influenza season be a B/Colorado/06/2017-like virus of the B/Victoria/2/87-lineage.