Components of the 2018-19 Northern Hemisphere influenza vaccine:
Vaccine viruses included in the 2018–19 U.S. trivalent influenza vaccines are:
- A/Michigan/45/2015 (H1N1)pdm09–like virus (unchanged from 2017-18)
- A/Singapore/INFIMH-16-0019/2016 (H3N2)-like virus (updated)
- B/Colorado/06/2017–like virus (Victoria lineage) (updated)
Quadrivalent vaccines contain an additional B virus, a B/Phuket/3073/2013–like virus (Yamagata lineage)
(unchanged)
.