Vaccine effectiveness (VE) against influenza B was derived separately for Victoria and Yamagata lineages across 8 seasons (2010-2011 to 2017-2018) in Canada when trivalent influenza vaccine was predominantly used. VE was ≥50% regardless of lineage match to circulating viruses, except when the vaccine strain was unchanged from the prior season.
Keywords: cross-protection; influenza B virus; influenza vaccine effectiveness; lineage; repeat vaccination.
© The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America.